#### Sample records for bright galaxy counts

1. The number counts and infrared backgrounds from infrared-bright galaxies

Extragalactic number counts and diffuse backgrounds at 25, 60, and 100 microns are predicted using new luminosity functions and improved spectral-energy distribution density functions derived from IRAS observations of nearby galaxies. Galaxies at redshifts z less than 3 that are like those in the local universe should produce a minimum diffuse background of 0.0085, 0.038, and 0.13 MJy/sr at 25, 60, and 100 microns, respectively. Models with significant luminosity evolution predict backgrounds about a factor of 4 greater than this minimum. 22 refs

2. The environment of Low Surface Brightness Galaxies

Rosenbaum, S. D.; Bomans, D. J.

2004-01-01

Using the Early Data Release of the Sloan Digital Sky Survey (SDSS) we investigated the clustering properties of Low Surface Brightness (LSB) galaxies in comparison to normal, High Surface Brightness (HSB) galaxies. We selected LSB galaxies and HSB galaxies with well measured redshifts from the SDSS data base and performed three-dimensional neighbour counting analysis within spheres of radii between 0.8 Mpc and 8.0 Mpc. As a second analysis method we used an N-th neighbour analysis with N var...

3. Bright Galaxies, Dark Matters

Rubin, Vera

In 1965, Vera Rubin was the first woman permitted to observe at Palomar Observatory. In the intervening years, she has become one of the world's finest and most respected astronomers. This particular collection of essays is compiled from work written over the past 15 years and deals with a variety of subjects in astronomy and astrophysics, specifically galaxies and dark matter. The book also contains biographical sketches of astronomers who have been colleagues and friends, providing a stimulating view of a woman in science. About the Author Since 1965 Vera Rubin has been a staff member at the Department of Terrestrial Magnetism of the Carnegie Institution of Washington. Dr. Rubin has authored nearly 200 papers on the structure of our galaxy, motions within other galaxies, and large scale motions in the universe. She has been a distinguished visiting astronomer at the Cerro Tololo Inter American Observatory in Chile; a Chancellor's Distinguished Professor at the University of California, Berkeley; a President's Distinguished Visitor at Vassar College; and a Beatrice Tinsley visiting professor at the University of Texas, Austin.

4. Bright galaxies, dark matters.

Rubin, V.

This book charts two extraordinary journeys: the road to a better understanding of the structure and composition of the universe, and V. Rubin's own pathbreaking career. The scientific papers included here offer an overview of the topic that has been the major focus of her career: the motions of stars within galaxies and the evidence from these motions that most of the matter in the universe is dark. Elsewhere the author examines some of the tools of her trade - from star charts to the Hubble Telescope to some of the observatories where she has worked. The concluding section, "The astronomical life", finds V. Rubin writing candidly about the demands and rewards of her career, offering insightful portraits of colleagues, friends, and other notable women in science.

5. Galaxy selection and the surface brightness distribution

McGaugh, S S; Schombert, J M

1995-01-01

Optical surveys for galaxies are biased against the inclusion of low surface brightness (LSB) galaxies. Disney (1976) suggested that the constancy of disk central surface brightness noticed by Freeman (1970) was not a physical result, but instead was an artifact of sample selection. Since LSB galaxies do exist, the pertinent and still controversial issue is if these newly discovered galaxies constitute a significant percentage of the general galaxy population. In this paper, we address this issue by determining the space density of galaxies as a function of disk central surface brightness. Using the physically reasonable assumption (which is motivated by the data) that central surface brightness is independent of disk scale length, we arrive at a distribution which is roughly flat (\\ie approximately equal numbers of galaxies at each surface brightness) faintwards of the Freeman (1970) value. Brightwards of this, we find a sharp decline in the distribution which is analogous to the turn down in the luminosity ...

6. The lowest surface brightness disc galaxy known

The discovery of a galaxy with a prominent bulge and a dominant extremely low surface brightness disc component is reported. The profile of this galaxy is very similar to the recently discovered giant low surface brightness galaxy Malin 1. The disc central surface brightness is found to be ∼ 26.4 Rμ, some 1.5 mag fainter than Malin 1 and thus by far the lowest yet observed. (author)

7. Surface Brightness Profiles of Seyfert Galaxies

Tugay, A V

2014-01-01

We built r-band surface brightness profiles by SDSS data for 16 Seyfert galaxies observed in Crimean Astrophysical Observatory. Obtained profiles can be used for finding more accurate lightcurves for these galaxies.

8. The surface brightness of spiral galaxies

The intrinsic surface brightness Ssub(e) of 500 disc galaxies (0<=T<=9) drawn from the Second Reference Catalogue is computed and it is shown that Ssub(e) does not correlate significantly with Msub(B), (B-V) or type. This is consistent with the notion that there is a heavy selection bias in favour of disc galaxies with that particular surface brightness which allows inclusion in the catalogue over the largest volume of space. (author)

9. The surface brightness of spiral galaxies

It is proposed that Freeman's discovery that the extrapolated central surface brightness of spiral galaxies is approximately constant can be simply explained if the galaxies contain a spheroidal component which dominates the light in their outer isophotes. Calculations of an effective central surface brightness indicate a wide spread of values. This requires either a wide spread in disc properties or significant spheroidal components or, most probably, both. (author)

10. The galaxy counts-in-cells distribution from the SDSS

Yang, Abel

2010-01-01

We determine the galaxy counts-in-cells distribution from the Sloan Digital Sky Survey (SDSS) for 3D spherical cells in redshift space as well as for 2D projected cells. We find that cosmic variance in the SDSS causes the counts-in-cells distributions in different quadrants to differ from each other by up to 20%. We also find that within this cosmic variance, the overall galaxy counts-in-cells distribution agrees with both the gravitational quasi-equilibrium distribution and the negative binomial distribution. We also find that brighter galaxies are more strongly clustered than if they were randomly selected from a larger complete sample that includes galaxies of all luminosities. The results suggest that bright galaxies could be in dark matter haloes separated by less than ~10 Mpc/h.

11. Galaxy evolution at low redshift?; 1, optical counts

Dennefeld, M

1996-01-01

We present bright galaxy number counts in the blue (16bright galaxies implying a high'' normalization of the local luminosity function. Our counts and colour distributions exhibit no large departure from what standard no-evolution models predict, removing the need for evolution of the galaxy population in the optical, out to Bj=21. This result disagrees with that of Maddox et al. (1990) on the APM catalog. We show that the APM and similar catalogs may be affected by a systematic magnitude scale error which would explain this discrepancy.

12. Star formation and the surface brightness of spiral galaxies

The (blue) surface brightness of spiral galaxies is significantly correlated with their Hα linewidth. This can be most plausibly interpreted as a correlation of surface brightness with star formation rate. There is also a significant difference in surface brightness between galaxies forming stars in a grand design spiral pattern and those with floc star formation regions. (author)

13. Vector perturbations of galaxy number counts

Durrer, Ruth

2016-01-01

We derive the contribution to relativistic galaxy number count fluctuations from vector and tensor perturbations within linear perturbation theory. Our result is consistent with the the relativistic corrections to number counts due to scalar perturbation, where the Bardeen potentials are replaced with line-of-sight projection of vector and tensor quantities. Since vector and tensor perturbations do not lead to density fluctuations the standard density term in the number counts is absent. We apply our results to vector perturbations which are induced from scalar perturbations at second order and give numerical estimates of their contributions to the power spectrum of relativistic galaxy number counts.

14. Selection effects in the bivariate brightness distribution for spiral galaxies

The joint distribution of total luminosity and characteristic surface brightness (the bivariate brightness distribution) is investigated for a complete sample of spiral galaxies in the Virgo cluster. The influence of selection and physical limits of various kinds on the apparent distribution are detailed. While the distribution of surface brightness for bright galaxies may be genuinely fairly narrow, faint galaxies exist right across the (quite small) range of accessible surface brightnesses so no statement can be made about the true extent of the distribution. The lack of high surface brightness bright galaxies in the Virgo sample relative to an overall RC2 sample (mostly field galaxies) supports the contention that the star-formation rate is reduced in the inner region of the cluster for environmental reasons. (author)

15. The surface brightness of spiral galaxies: Pt. 4

Using measurements from IRAS correlations are found between optical surface brightness and both infrared-to-optical flux ratio and infrared colour temperature, in the sense that galaxies with high surface brightness have higher FIR emission and higher temperatures. (author)

16. Submillimeter Galaxy Number Counts and Magnification by Galaxy Clusters

Lima, Marcos; Devlin, Mark; Aguirre, James

2010-01-01

We present an analytical model which reproduces measured galaxy number counts from surveys in the wavelength range of 500 micron to 2 mm. The model involves a single high-redshift galaxy population with a Schechter luminosity function which has been gravitationally lensed by galaxy clusters in the mass range 10^13 to 10^15 Msun. This simple model reproduces both the low flux and the high flux end of the number counts reported by the BLAST, SCUBA, AzTEC and the SPT surveys. In particular, our model accounts for the most luminous galaxies detected by SPT as the result of high magnifications by galaxy clusters (magnification factors of 10-30). This interpretation implies that submillimeter and millimeter surveys of this population may prove to be a useful addition to ongoing cluster detection surveys. The model also implies that the bulk of submillimeter galaxies detected at wavelengths larger than 500 micron lie at redshifts greater than 2.

17. New Low Surface Brightness Dwarf Galaxies Detected Around Nearby Spirals

Karachentsev, I. D.; Riepe, P.; Zilch, T.; Blauensteiner, M.; Elvov, M.; Hochleitner, P.; Hubl, B.; Kerschhuber, G.; Küppers, S.; Neyer, F.; Pölzl, R.; Remmel, P.; Schneider, O.; Sparenberg, R.; Trulson, U.

2015-01-01

We conduct a survey of low surface brightness (LSB) satellite galaxies around the Local Volume massive spirals using long exposures with small amateur telescopes. We identified 27 low and very low surface brightness objects around the galaxies NGC,672, 891, 1156, 2683, 3344, 4258, 4618, 4631, and 5457 situated within 10 Mpc from us, and found nothing new around NGC,2903, 3239, 4214, and 5585. Assuming that the dwarf candidates are the satellites of the neighboring luminous galaxies, their abs...

18. Bright X-ray galaxies in SDSS filaments

Tugay, A. V.

2013-01-01

Eighteen bright X-ray emitting galaxies were found in nearby filaments within SDSS region. Basic X-ray spectral parameters were estimated for these galaxies using power law model with photoelectric absorption. A close pair of X-ray galaxies was found.

19. Low surface brightness galaxies in the Fornax Cluster: automated galaxy surface photometry

A sample is presented of low surface brightness galaxies (with extrapolated central surface brightness fainter than 22.0 Bμ) in the Fornax Cluster region which has been measured by the APM machine. Photometric parameters, namely profile shape, scale length, central brightness and total magnitude, are derived for the sample galaxies and correlations between the parameters of low surface brightness dwarf galaxies are discussed, with particular reference to the selection limits. Contrary to previous authors we find no evidence for a luminosity-surface brightness correlation in the sense of lower surface brightness galaxies having lower luminosities and scale sizes. In fact, the present data suggest that it is the galaxies with the largest scale lengths which are more likely to be of very low surface brightness. In addition, the larger scale length galaxies occur preferentially towards the centre of the Cluster. (author)

20. Survival analysis of the optical brightness of GRB host galaxies

Racz, I I; Bagoly, Z; Toth, L V

2015-01-01

We studied the unbiased optical brightness distribution which was calculated from the survival analysis of host galaxies and its relationship with the Swift GRB data of the host galaxies observed by the Keck telescopes. Based on the sample obtained from merging the Swift GRB table and the Keck optical data we also studied the dependence of this distribution on the data of the GRBs. Finally, we compared the HGs distribution with standard galaxies distribution which is in the DEEP2 galaxies catalog.

1. Low surface brightness galaxies in the cluster A1367

We have obtained deep CCD frames of apparently blank regions of sky in the hope of detecting very low surface brightness (LSB) objects in the cluster A1367. We discuss our data reduction, and image detection and selection techniques. If the galaxies detected are actually cluster members then they are dwarfs and the conclusions of a previous paper on the Fornax cluster are essentially confirmed. One area of variance is that the lowest surface brightness galaxies do not appear to be preferentially concentrated towards the cluster centre. This can be explained by there being a much larger density of dwarf galaxies over this bright galaxy-rich region of the universe. We find over our small area approximately four times as many LSB galaxies as would be expected from our Fornax data. We speculate on the possible origin and likely intensity of intergalactic light within clusters. (author)

2. Do Baryons Alter the Halos of Low Surface Brightness Galaxies?

de Naray, Rachel Kuzio

2011-01-01

High-quality observations of dark matter-dominated low surface brightness (LSB) galaxies indicate that, in contrast to the triaxial, centrally-concentrated cuspy halos formed in collisionless simulations of halo assembly, these galaxies reside in round, roughly constant density cored halos. In order to reconcile these data with galaxy formation in the context of LCDM, processes that alter the shape and density structure of the inner halo are required. We compile observational properties of LSB galaxies to evaluate the plausibility that a previously higher baryonic mass content and feedback from star formation can modify the dark matter halos of these galaxies. We also compare the properties of bulgeless disk galaxies formed in recent simulations to the LSB galaxy sample. We find that observational constraints on LSB galaxy star formation histories, structure, and kinematics make it difficult for baryonic physics to sphericalize and decrease the central density of the dark matter halos of LSB galaxies.

3. Giant Low Surface Brightness Galaxies: Evolution in Isolation

M. Das

2013-03-01

Giant Low Surface Brightness (GLSB) galaxies are amongst the most massive spiral galaxies that we know of in our Universe. Although they fall in the class of late type spiral galaxies, their properties are far more extreme. They have very faint stellar disks that are extremely rich in neutral hydrogen gas but low in star formation and hence low in surface brightness. They often have bright bulges that are similar to those found in early type galaxies. The bulges can host low luminosity Active Galactic Nuclei (AGN) that have relatively low mass black holes. GLSB galaxies are usually isolated systems and are rarely found to be interacting with other galaxies. In fact many GLSB galaxies are found under dense regions close to the edges of voids. These galaxies have very massive dark matter halos that also contribute to their stability and lack of evolution. In this paper we briefly review the properties of this unique class of galaxies and conclude that both their isolation and their massive dark matter halos have led to the low star formation rates and the slower rate of evolution in these galaxies.

4. The surface brightness of 1550 galaxies in Fornax: automated galaxy surface photometry: Pt. 2

A survey of a complete sample of galaxies in the region of the Fornax cluster is presented. Measurements with the Automatic Plate Measuring machine are used to derive the observed distribution of galaxy surface brightness for 1550 objects. Corrections for surface brightness dependent selection effects are then made in order to estimate the true distribution. It is found that the sample (with 16.6 ≤ Msub(APM) ≤ 19.1) is divided into two distinct populations. The 'normal' galaxies with extrapolated central surface brightness Ssub(x) ≤ 22.5 Bμ form a uniformly distributed background of field galaxies. Low surface brightness galaxies (Ssub(x) ≥ 22.5 Bμ), on the other hand, are strongly clumped about the cluster centre. There appear to be few low surface brightness field galaxies. (author)

5. Far-Ultraviolet Number Counts of Field Galaxies

Voyer, Elysse N; Teplitz, Harry I; Siana, Brian D; de Mello, Duilia F

2011-01-01

The far-ultraviolet (FUV) number counts of galaxies constrain the evolution of the star-formation rate density of the universe. We report the FUV number counts computed from FUV imaging of several fields including the Hubble Ultra Deep Field, the Hubble Deep Field North, and small areas within the GOODS-North and -South fields. These data were obtained with the Hubble Space Telescope Solar Blind Channel of the Advance Camera for Surveys. The number counts sample a FUV AB magnitude range from 21-29 and cover a total area of 15.9 arcmin^2, ~4 times larger than the most recent HST FUV study. Our FUV counts intersect bright FUV GALEX counts at 22.5 mag and they show good agreement with recent semi-analytic models based on dark matter "merger trees" by Somerville et al. (2011). We show that the number counts are ~35% lower than in previous HST studies that use smaller areas. The differences between these studies are likely the result of cosmic variance; our new data cover more lines of sight and more area than pre...

6. Global properties of infrared bright galaxies

Young, Judith S.; Xie, Shuding; Kenney, Jeffrey D. P.; Rice, Walter L.

1989-01-01

Infrared flux densities of 182 galaxies, including 50 galaxies in the Virgo cluster, were analyzed using IRAS data for 12, 25, 60, and 100 microns, and the results were compared with data listed in the Point Source Catalog (PSC, 1985). In addition, IR luminosities, L(IRs), colors, and warm dust masses were derived for these galaxies and were compared with the interstellar gas masses and optical luminosities of the galaxies. It was found that, for galaxies whose optical diameter measures between 5 and 8 arcmin, the PSC flux densities are underestimated by a factor of 2 at 60 microns, and by a factor of 1.5 at 100 microns. It was also found that, for 49 galaxies, the mass of warm dust correlated well with the H2 mass, and that L(IR) correlated with L(H-alpha), demonstrating that the L(IR) measures the rate of star formation in these galaxies.

7. The Galaxy Counts-in-cells Distribution from the Sloan Digital Sky Survey

Yang, Abel; Saslaw, William C.

2011-03-01

We determine the galaxy counts-in-cells distribution from the Sloan Digital Sky Survey (SDSS) for three-dimensional spherical cells in redshift space as well as for two-dimensional projected cells. We find that cosmic variance in the SDSS causes the counts-in-cells distributions in different quadrants to differ from each other by up to 20%. We also find that within this cosmic variance, the overall galaxy counts-in-cells distribution agrees with both the gravitational quasi-equilibrium distribution and the negative binomial distribution. We also find that brighter galaxies are more strongly clustered than if they were randomly selected from a larger complete sample that includes galaxies of all luminosities. The results suggest that bright galaxies could be in dark matter halos separated by less than ~10 h -1 Mpc.

8. Combining cluster number counts and galaxy clustering

Lacasa, Fabien

2016-01-01

We present a detailed modelling of the joint covariance matrix between cluster number counts and the galaxy angular power spectrum. To this end, we use a Halo Model framework complemented by a Halo Occupation Distribution model (HOD), and we work in full-sky. We demonstrate the importance of accounting for non-Gaussianity to produce accurate covariance predictions, as the Gaussian part of the covariance can in fact become subdominant in certain configurations. We discuss in particular the case of the super-sample covariance (SSC), including the effects of galaxy shot-noise, halo second order bias and non-local bias, and demonstrating interesting mathematical properties. Using the joint covariance matrix and a Fisher matrix methodology, we examine the prospects of combining these two probes to constrain cosmological and HOD parameters. We find that the combination indeed results in noticeable better constraints, in particular because the cross-covariance introduces a synergy between the probes on small scales....

9. Morphological Number Counts of Galaxies in the Hubble Deep Field South

Lee, M G; Lee, Myung Gyoon; Hwang, Narae

2000-01-01

We present a study of photometric properties of the galaxies in the Hubble Deep Field South (HDFS) based on the released WFPC2 images obtained with the Hubble Space Telescope (HST). We have classified about 340 galaxies with $I<26$ mag in the HDFS as well as about 400 galaxies in the Hubble Deep Field North (HDFN) using the visual classification supplemented by inspection of the surface brightness profiles of the galaxies. Galaxy population statistics and morphological number counts for the HDFS are found to be similar to be those for the HDFN. We have also determined photometrically the redshifts of the galaxies with $I<26$ mag in the HDFS and the HDFN using the empirical training set method. Redshift distribution, color-redshift relation, and magnitude-redshift for each type of galaxies are investigated.

10. Bright galaxies in the Fornax cluster. Automated galaxy surface photometry: Pt. 7

We have determined surface-brightness profiles for all galaxies down to magnitude B = 16 in the central region of the Fornax cluster. Using existing redshift data, we have determined the distributions of surface brightness for both the whole sample and for cluster disc galaxies only. Although both distributions peak at extrapolated central surface brightness ∼ 21.7B mag/arcsec2 (the canonical result), it is shown that they are, in fact, consistent with very broad distributions of disc central surface brightness once selection effects and the effects of bulge contamination of the profile are taken into account. (author)

11. Estimation of the Space Density of Low Surface Brightness Galaxies

Briggs, F H

1997-01-01

The space density of low surface brightness and tiny gas-rich dwarf galaxies are estimated for two recent catalogs: The Arecibo Survey of Northern Dwarf and Low Surface Brightness Galaxies (Schneider, Thuan, Magri & Wadiak 1990) and The Catalog of Low Surface Brightness Galaxy, List II (Schombert, Bothun, Schneider & McGaugh 1992). The goals are (1) to evaluate the additions to the completeness of the Fisher and Tully (1981) 10 Mpc Sample and (2) to estimate whether the density of galaxies contained in the new catalogs adds a significant amount of neutral gas mass to the the inventory of HI already identified in the nearby, present-epoch universe. Although tiny dwarf galaxies (M_HI < ~10^7 solar masses) may be the most abundant type of extragalactic stellar system in the nearby Universe, if the new catalogs are representative, the LSB and dwarf populations they contain make only a small addition (<10%) to the total HI content of the local Universe and probably constitute even smaller fractions o...

12. The bispectrum of relativistic galaxy number counts

Di Dio, Enea; Marozzi, Giovanni; Montanari, Francesco

2016-01-01

Starting from the relativistic galaxy number counts to second order in cosmological perturbation theory which we have determined in a previous paper, we discuss the dominant terms on sub-Hubble scales and on intermediate to large redshifts. In particular, we determine their contribution to the bispectrum. In addition to the terms already known from Newtonian second order perturbation theory, we find that there are a series of additional lensing-like' terms which contribute to the bispectrum. We derive analytical expressions for the full leading order bispectrum and we evaluate it numerically for different configurations, indicating how they can be measured with upcoming surveys. In particular, the new lensing-like' terms are not negligible within large window functions and even dominate the bispectrum at well separated redshifts. This offers us the possibility to measure them in future surveys.

13. Poor cluster of galaxies containing four absolutely bright Markaryan galaxies

The Zwicky cluster Zw 1122.3 + 6317, which contains four Markaryan galaxies, is discussed. Radial velocities are determined for three galaxies in the region of the sky occupied by this cluster. It is shown that the cluster is very open and consists mainly of spirals, that some compact ellipticals are possible cluster members, and that the Markarian galaxies are among the brightest cluster members. Spatial and kinematic characteristics of the cluster are estimated, including a mean recession velocity of 3557 km/s, a radial-velocity dispersion of 219 km/s, a virial mass of 92 trillion solar masses, a crossing time of 2.9 billion years, a luminosity of 1.1 trillion suns, and an M/L ratio of 84 (in solar units). The possibility is noted that this cluster might actually be two groups of galaxies, with mean recession velocities of approximately 3350 and 3750 km/s, projected onto each other

14. The HI dominated Low Surface Brightness Galaxy KKR17

Lam, Man I; Yang, Ming; Zhou, Zhi-Min; Du, Wei; Zhu, Yi-Nan

2014-01-01

We present new narrow-band (H$\\alpha$ and [OIII]) imagings and optical spectrophotometry of HII regions for a gas-rich low surface brightness irregular galaxy, KKR 17. The central surface brightness of the galaxy is $\\mu_0(B)$ = 24.15 $\\pm$0.03 mag~sec$^{-2}$. The galaxy was detected by \\emph{Arecibo Legacy Fast ALFA survey} (ALFALFA), and its mass is dominated by neutral hydrogen (HI) gas. In contrast, both the stellar masses of the bright HII and diffuse stellar regions are small. In addition, the fit to the spectral energy distribution to each region shows the stellar populations of HII and diffuse regions are different. The bright HII region contains a large fraction of O-type stars, revealing the recent strong star formation, whereas the diffuse region is dominated by median age stars, which has a typical age of $\\sim$ 600 Myrs. Using the McGaugh's abundance model, we found that the average metallicity of KKR 17 is 12 + (O/H) = 8.0 $\\pm$ 0.1. The star formation rate of KKR 17 is 0.21$\\pm$0.04 M$_{\\odot}$...

15. Statistical Properties of Bright Galaxies in the SDSS Photometric System

Shimasaku, K; Doi, M; Hamabe, M; Ichikawa, T; Okamura, S; Sekiguchi, M; Yasuda, N

2001-01-01

We investigate the photometric properties of 456 bright galaxies using imaging data recorded during the commissioning phase of the Sloan Digital Sky Survey (SDSS). Morphological classification is carried out by correlating results of several human classifiers. Our purpose is to examine the statistical properties of color indices, scale lengths, and concentration indices as functions of morphology for the SDSS photometric system. We find that $u'-g'$, $g'-r'$, and $r'-i'$ colors of SDSS galaxies match well with those expected from the synthetic calculation of spectroscopic energy distribution of template galaxies and with those transformed from $UBVR_CI_C$ color data of nearby galaxies. The agreement is somewhat poor, however, for $i'-z'$ color band with a discrepancy of $0.1-0.2$ mag. With the aid of the relation between surface brightness and radius obtained by Kent (1985), we estimate the averages of the effective radius of early type galaxies and the scale length of exponential disks both to be 2.6 kpc for...

16. Multiwavelength investigations of co-evolution of bright custer galaxies

Hashimoto, Yasuhiro; Boehringer, Hans

2014-01-01

We report a systematic multi-wavelength investigation of environments of the brightest cluster galaxies (BCGs), using the X-ray data from the Chandra archive, and optical images taken with 34'x 27' field-of-view Subaru Suprime-Cam. Our goal is to help understand the relationship between the BCGs and their host clusters, and between the BCGs and other galaxies, to eventually address a question of the formation and co-evolution of BCGs and the clusters. Our results include: 1) Morphological variety of BCGs, or the second or the third brightest galaxy (BCG2, BCG3), is comparable to that of other bright red sequence galaxies, suggesting that we have a continuous variation of morphology between BCGs, BCG2, and BCG3, rather than a sharp separation between the BCG and the rest of the bright galaxies. 2) The offset of the BCG position relative to the cluster centre is correlated to the degree of concentration of cluster X-ray morphology (Spearman rho = -0.79), consistent with an interpretation that BCGs tend to be of...

17. The Environment of Sy1, Sy2 & Bright IRAS Galaxies

Koulouridis, E; Plionis, M; Dultzin, D; Krongold, Y; Goudis, C; Chatzichristou, E

2008-01-01

We present a 3-dimensional study of the local (< 100 kpc) environment of Sy1, Sy2 and Bright IRAS Galaxies. For this purpose we use three galaxy samples (Sy1, Sy2, BIRG) located at high galactic latitudes as well as three control sample of non-active galaxies having the same morphological, redshift and diameter size distributions as the corresponding Seyfert or BIRG sample. Using the CfA2 and SSRS galaxy catalogues as well as our own spectroscopic observations, we find that the fraction of BIRGs with a close neighbor is significantly higher than that of their control sample. We also find that Sy2 galaxies demonstrate the same behaviour with BIRG galaxies but not with Sy1s which do not show any excess of companions with respect to their control sample galaxies. An additional analysis of the relation between FIR colors and activity type of the BIRG's shows a significant difference between the colors of strongly-interacting and non-interacting starbursts and a resemblance between the colors of non-interacting...

18. The dearth of nuclear star clusters in bright galaxies

Arca-Sedda, M.; Capuzzo-Dolcetta, R.; Spera, M.

2016-03-01

We investigate the interaction of a massive globular cluster (GC) with a super massive black hole (SMBH), located at the centre of its host galaxy, by means of direct N-body simulations. The results show that tidal distortions induced by the stellar background and the SMBH act on a time shorter than that of dynamical friction decay for a 106 M⊙ GC whenever the SMBH mass exceeds ˜108 M⊙. This implies an almost complete dissolution of the infalling GC before it reaches the inner region (≲5 pc) of the parent galaxy. The generalization of this result to a larger sample of infalling GCs shows that such destructive process may prevent the formation and growth of a bright galactic nucleus. Another interesting, serendipitous, result we obtained is that the close interaction between the SMBH and the GC produces a wave' of stars that escape from the cluster and, in a fraction, even from the whole galaxy.

19. The source counts of submillimetre galaxies detected at 1.1 mm

Scott, K S; Aretxaga, I; Austermann, J E; Chapin, E L; Dunlop, J S; Ezawa, H; Halpern, M; Hatsukade, B; Hughes, D H; Kawabe, R; Kim, S; Kohno, K; Lowenthal, J D; Montana, A; Nakanishi, K; Oshima, T; Sanders, D; Scott, D; Scoville, N; Tamura, Y; Welch, D; Yun, M S; Zeballos, M

2012-01-01

The source counts of galaxies discovered at sub-millimetre and millimetre wavelengths provide important information on the evolution of infrared-bright galaxies. We combine the data from six blank-field surveys carried out at 1.1 mm with AzTEC, totalling 1.6 square degrees in area with root-mean-square depths ranging from 0.4 to 1.7 mJy, and derive the strongest constraints to date on the 1.1 mm source counts at flux densities S(1100) = 1-12 mJy. Using additional data from the AzTEC Cluster Environment Survey to extend the counts to S(1100) ~ 20 mJy, we see tentative evidence for an enhancement relative to the exponential drop in the counts at S(1100) ~ 13 mJy and a smooth connection to the bright source counts at >20 mJy measured by the South Pole Telescope; this excess may be due to strong lensing effects. We compare these counts to predictions from several semi-analytical and phenomenological models and find that for most the agreement is quite good at flux densities > 4 mJy; however, we find significant d...

20. Quasars near bright galaxies - results from the Jodrell Bank 966-MHz survey

The distribution of bright galaxies around quasars from the Jodrell Bank 966-MHz survey has been investigated. No statistical evidence is found to support the hypothesis that nearby bright galaxies and quasars are physically associated. Some selection effects which lead to a correlation between pair separation and galaxy redshift are discussed. (author)

1. Dark matter within high surface brightness spiral galaxies

Kranz, T; Rix, H W; Kranz, Thilo; Slyz, Adrianne; Rix, Hans-Walter

2003-01-01

We present results from a detailed dynamical analysis of five high surface brightness, late type spirals, studied with the aim to quantify the luminous-to-dark matter ratio inside their optical radii. The galaxies' stellar light distribution and gas kinematics have been observed and compared to hydrodynamic gas simulations, which predict the 2D gas dynamics arising in response to empirical gravitational potentials, which are combinations of differing stellar disk and dark halo contributions. The gravitational potential of the stellar disk was derived from near-infrared photometry, color-corrected to constant (M/L); the dark halo was modelled by an isothermal sphere with a core. Hydrodynamic gas simulations were performed for each galaxy for a sequence of five different mass fractions of the stellar disk and for a wide range of spiral pattern speeds. These two parameters mainly determine the modelled gas distribution and kinematics. The agreement between the non-axisymmetric part of the simulated and observed ...

2. The bright galaxy population of five medium redshift clusters. II. Quantitative Galaxy Morphology

Ascaso, B; Moles, M; Sánchez-Janssen, R; Bettoni, D

2009-01-01

Aims: Following the study already presented in our previous paper, based on the Nordic Optical Telescope (NOT) sample, which consists of five clusters of galaxies within the redshift range 0.18 $\\leq$ z $\\leq$ 0.25, imaged in the central 0.5-2 Mpc in very good seeing conditions, we have studied the quantitative morphology of their bright galaxy population Methods: We have analyzed the surface brightness profiles of the galaxy population in those clusters. Previously, we have performed simulations in order to check the reliability of the fits. We have also derived a quantitative morphological classification. Results: The structural parameters derived from these analysis have been analyzed. We have obtained that the structural parameters of E/S0 galaxies are similar to those showed by galaxies in low redshift clusters. However, the disc scales are different. In particular, the scales of the discs of galaxies at medium redshift clusters are statistically different than those located in similar galaxies in the Co...

3. The properties of a large sample of low surface brightness galaxies from SDSS

Liang, Y C; Chen, X Y; Gao, D; Hammer, F; Liu, F S; Hu, J Y; Deng, L C; Zhang, B

2009-01-01

A large sample of low surface brightness (LSB) disk galaxies is selected from SDSS with B-band central surface brightness mu_0(B) from 22 to 24.5 mag arcsec^(-2). Some of their properties are studied, such as magnitudes, surface brightness, scalelengths, colors, metallicities, stellar populations, stellar masses and multiwavelength SEDs from UV to IR etc. These properties of LSB galaxies have been compared with those of the galaxies with higher surface brightnesses. Then we check the variations of these properties following surface brightness.

4. Surface Brightness Profiles of Dwarf Galaxies: I. Profiles and Statistics

Herrmann, Kimberly A; Elmegreen, Bruce G

2013-01-01

Radial surface brightness profiles of spiral galaxies are classified into three types: (I) single exponential, or the light falls off with one exponential to a break before falling off (II) more steeply, or (III) less steeply. Profile breaks are also found in dwarf disks, but some dwarf Type IIs are flat or increasing out to a break before falling off. Here we re-examine the stellar disk profiles of 141 dwarfs: 96 dwarf irregulars (dIms), 26 Blue Compact Dwarfs (BCDs), and 19 Magellanic-type spirals (Sms). We fit single, double, or even triple exponential profiles in up to 11 passbands: GALEX FUV and NUV, ground-based UBV JHK and H{\\alpha}, and Spitzer 3.6 and 4.5 {\\mu}m. We find that more luminous galaxies have brighter centers, larger inner and outer scale lengths, and break at larger radii; dwarf trends with M_B extend to spirals. However, the V-band break surface brightness is independent of break type, M_B, and Hubble type. Dwarf Type II and III profiles fall off similarly beyond the breaks but have diff...

5. New low surface brightness dwarf galaxies in the Centaurus group

Müller, Oliver; Binggeli, Bruno

2016-01-01

We conducted an extensive CCD search for faint, unresolved dwarf galaxies of very low surface brightness in the whole Centaurus group region encompassing the Cen A and M 83 subgroups lying at a distance of roughly 4 and 5 Mpc, respectively. The aim is to significantly increase the sample of known Centaurus group members down to a fainter level of completeness, serving as a basis for future studies of the 3D structure of the group. Following our previous survey of 60 square degrees covering the M 83 subgroup, we extended and completed our survey of the Centaurus group region by imaging another 500 square degrees area in the g and r bands with the wide-field Dark Energy Survey Camera at the 4m Blanco telescope at CTIO. The limiting central surface brightness reached for suspected Centaurus members is $\\mu_r \\approx 29$ mag arcsec$^{-2}$, corresponding to an absolute magnitude $M_r \\approx -9.5$. The images were enhanced using different filtering techniques. We found 41 new dwarf galaxy candidates, which togethe...

6. SURFACE BRIGHTNESS PROFILES OF DWARF GALAXIES. I. PROFILES AND STATISTICS

Radial surface brightness profiles of spiral galaxies are classified into three types: (I) single exponential, or the light falls off with one exponential to a break before falling off (II) more steeply, or (III) less steeply. Profile breaks are also found in dwarf disks, but some dwarf Type IIs are flat or increasing out to a break before falling off. Here we re-examine the stellar disk profiles of 141 dwarfs: 96 dwarf irregulars (dIms), 26 Blue Compact Dwarfs (BCDs), and 19 Magellanic-type spirals (Sms). We fit single, double, or even triple exponential profiles in up to 11 passbands: GALEX FUV and NUV, ground-based UBVJHK and Hα, and Spitzer 3.6 and 4.5 μm. We find that more luminous galaxies have brighter centers, larger inner and outer scale lengths, and breaks at larger radii; dwarf trends with MB extend to spirals. However, the V-band break surface brightness is independent of break type, MB , and Hubble type. Dwarf Type II and III profiles fall off similarly beyond the breaks but have different interiors and IIs break ∼twice as far as IIIs. Outer Type II and III scale lengths may have weak trends with wavelength, but pure Type II inner scale lengths clearly decrease from the FUV to visible bands whereas Type III inner scale lengths increase with redder bands. This suggests the influence of different star formation histories on profile type, but nonetheless the break location is approximately the same in all passbands. Dwarfs continue trends between profile and Hubble types such that later-type galaxies have more Type II but fewer Type I and III profiles than early-type spirals. BCDs and Sms are over-represented as Types III and II, respectively, compared to dIms

7. Dependence of the bright end of galaxy luminosity function on cluster dynamical state

Wen, Z L

2014-01-01

Luminosity function of cluster galaxies provides a fundamental constraint on galaxy evolution in cluster environments. By using the bright member galaxies of a large sample of rich clusters identified from Sloan Digital Sky Survey, we obtain the bright end of composite luminosity functions of cluster galaxies, and study their dependence on cluster dynamical state. After a redshift-evolution correction of absolute magnitude, the luminosity function of member galaxies can be well fitted by a Schechter function when the brightest cluster galaxies (BCGs) are excluded. The absolute magnitudes of BCGs follow a Gaussian function with a characteristic width of about 0.36 mag. We find that the luminosity function of galaxies in more relaxed clusters has a fainter characteristic absolute magnitude (M_{\\ast}), and these clusters have fewer bright non-BCG member galaxies but a brighter BCG. Our results suggest the co-evolution of galaxy population with cluster dynamical state and somewhat support the hierarchical formati...

8. The dearth of nuclear star clusters in bright galaxies

Arca-Sedda, Manuel; Spera, Mario

2015-01-01

We investigate the interaction of a massive globular cluster (GC) with a super massive black hole (SMBH), located at the centre of its host galaxy, by means of direct $N$-body simulations. The results show that tidal distortions induced by the stellar background and the SMBH act on a time shorter than that of dynamical friction decay for a $10^6$ M$_\\odot$ GC whenever the SMBH mass exceeds $\\sim 10^8$ M$_\\odot$. This implies an almost complete dissolution of the infalling GC before it reaches the inner region ($\\lesssim 5$ pc) of the parent galaxy. The generalization of this result to a larger sample of infalling GCs shows that such destructive process may prevent the formation and growth of a bright galactic nucleus. Another interesting, serendipitous, result we obtained is that the close interaction between the SMBH and the GC produces a wave'' of stars that escape from the cluster and, in a fraction, even from the whole galaxy.

9. A universal threshold for the formation of bright galaxies

Zhao, HongSheng; Dobbs, Clare

2008-01-01

The tight correlation between galaxy bulges and their central black hole masses likely emerges in a phase of rapid collapse and starburst at high redshift. The correlation is due to the balance of gravity on gas with the feedback force from starbursts and the wind from the black hole. The tightness suggests a universal scale of gravity on gas during this phase. The scalar field in some co-variant versions of MOND can create the mirage of a Newtonian effective dark halo with a "dark" gravity being a nearly universal value ~ (1.2/alpha)* 10^{-10} m sec^-2 for bright galaxies, where alpha ~ 1-3 is a fundamental constant in the Lagrangian of the theory. A dark gravity of similar order of magnitude which is insensitive to redshift can also be generated by the real 1/r cusps of Cold Dark Matter (CDM) halos. However the values generally have a larger scatter, which increases with the mass of the galaxies and adiabatic contraction effects of gas collapse. We show with a toy analytical model and a hydrodynamical simul...

10. Surface brightness fluctuation distances for nearby dwarf elliptical galaxies

Jerjen, H; Takalo, L; Coleman, M; Valtonen, M J; Jerjen, Helmut; Rekola, Rami; Takalo, Leo; Coleman, Matthew; Valtonen, Mauri

2001-01-01

We obtained B and R-band CCD images for the dwarf elliptical (dE) galaxies DDO44, UGC4998, KK98_77, DDO71, DDO113, and UGC7356 at the NOT. Using Fourier analysis technique we measure stellar R-band surface brightness fluctuations (SBFs) and magnitudes in 29 different fields of the galaxies. Independent tip of the red giant branch distances for DDO44, KK98_77, DDO71 are used to convert their set of apparent into absolute SBF magnitudes. The results are combined with the local (B-R) colours and compared with the (B-R)-\\bar{M}_R relation for mainly old, metal-poor stellar populations as predicted by Worthey's population synthesis models using Padova isochrones. While the colour dependency of the theoretical relation is confirmed by the empirical data, we find a systematic zero point offset between observations and theory in the sense that models are too faint by 0.13+-0.02 mag. Based on these findings we establish a new semiempirical calibration of the SBF method as distance indicator for dE galaxies with an est...

11. HerMES: Deep Galaxy Number Counts from a P(D) Fluctuation Analysis of SPIRE Science Demonstration Phase Observations

Glenn, J; Bethermin, M; Altieri, B; Amblard, A; Arumugam, V; Aussel, H; Babbedge, T; Blain, A; Bock, J; Boselli, A; Buat, V; Castro-Rodriguez, N; Cava, A; Chanial, P; Clements, D L; Conversi, L; Cooray, A; Dowell, C D; Dwek, E; Eales, S; Elbaz, D; Ellsworth-Bowers, T P; Fox, M; Franceschini, A; Gear, W; Griffin, M; Halpern, M; Hatziminaoglou, E; Ibar, E; Isaak, K; Ivison, R J; Lagache, G; Laurent, G; Levenson, L; Lu, N; Madden, S; Maffei, B; Mainetti, G; Marchetti, L; Marsden, G; Nguyen, H T; O'Halloran, B; Oliver, S J; Omont, A; Page, M J; Panuzzo, P; Papageorgiou, A; Pearson, C P; Perez-Fournon, I; Pohlen, M; Rigopoulou, D; Rizzo, D; Roseboom, I G; Rowan-Robinson, M; Portal, M Sanchez; Schulz, B; Scott, Douglas; Seymour, N; Shupe, D L; Smith, A J; Stevens, J A; Symeonidis, M; Trichas, M; Tugwell, K E; Vaccari, M; Valtchanov, I; Vieira, J D; Vigroux, L; Wang, L; Ward, R; Wright, G; Xu, C K; Zemcov, M

2010-01-01

Dusty, star forming galaxies contribute to a bright, currently unresolved cosmic far-infrared background. Deep Herschel-SPIRE images designed to detect and characterize the galaxies that comprise this background are highly confused, such that the bulk lies below the classical confusion limit. We analyze three fields from the HerMES programme in all three SPIRE bands (250, 350, and 500 microns); parameterized galaxy number count models are derived to a depth of ~2 mJy/beam, approximately 4 times the depth of previous analyses at these wavelengths, using a P(D) (probability of deflection) approach for comparison to theoretical number count models. Our fits account for 64, 60, and 43 per cent of the far-infrared background in the three bands. The number counts are consistent with those based on individually detected SPIRE sources, but generally inconsistent with most galaxy number counts models, which generically overpredict the number of bright galaxies and are not as steep as the P(D)-derived number counts. Cl...

12. DEEP GALEX OBSERVATIONS OF THE COMA CLUSTER: SOURCE CATALOG AND GALAXY COUNTS

We present a source catalog from a deep 26 ks Galaxy Evolution Explorer (GALEX) observation of the Coma cluster in the far-UV (FUV; 1530 A) and near-UV (NUV; 2310 A) wavebands. The observed field is centered ∼0.09 (1.6 Mpc) southwest of the Coma core in a well-studied region of the cluster known as 'Coma-3'. The entire field is located within the apparent virial radius of the Coma cluster, and has optical photometric coverage with Sloan Digital Sky Survey (SDSS) and deep spectroscopic coverage to r ∼ 21. We detect GALEX sources to NUV = 24.5 and FUV = 25.0, which corresponds to a star formation rate of ∼10-3 M sun yr-1 for galaxies at the distance of Coma. We have assembled a catalog of 9700 galaxies with GALEX and SDSS photometry, including 242 spectroscopically confirmed Coma member galaxies that span a large range of galaxy types from giant spirals and elliptical galaxies to dwarf irregular and early-type galaxies. The full multi-wavelength catalog (cluster plus background galaxies) is ∼80% complete to NUV = 23 and FUV = 23.5. The GALEX images presented here are very deep and include detections of many resolved cluster members superposed on a dense field of unresolved background galaxies. This required a two-fold approach to generating a source catalog: we used a Bayesian deblending algorithm to measure faint and compact sources (using SDSS coordinates as position prior), and used the GALEX pipeline catalog for bright and/or extended objects. We performed simulations to assess the importance of systematic effects (e.g., object blends, source confusion, Eddington Bias) that influence the source detection and photometry when using both methods. The Bayesian deblending method roughly doubles the number of source detections and provides reliable photometry to a few magnitudes deeper than the GALEX pipeline catalog. This method is free from source confusion over the UV magnitude range studied here; we estimate that the GALEX pipeline catalogs are confusion

13. The local hole revealed by galaxy counts and redshifts

Whitbourn, J. R.; Shanks, T.

2014-01-01

The redshifts of ≈250 000 galaxies are used to study the local hole and its associated peculiar velocities. The sample, compiled from the 6dF Galaxy Redshift Survey and Sloan Digital Sky Survey, provides wide sky coverage to a depth of ≈300 h-1 Mpc. We have therefore examined K- and r-limited galaxy redshift distributions and number counts to map the local density field. Comparing observed galaxy n(z) distributions to homogeneous models in three large regions of the high-latitude sky, we find evidence for underdensities ranging from ≈4-40 per cent in these regions to depths of ≈150 h-1 Mpc with the deepest underdensity being over the southern Galactic cap. Using the Galaxy and Mass Assembly survey, we then establish the normalization of galaxy counts at fainter magnitudes and thus confirm that the underdensity over all three fields at K < 12.5 is ≈15 ± 3 per cent. Finally, we further use redshift catalogues to map sky-averaged peculiar velocities over the same areas using the average redshift-magnitude, overline{z}(m), technique of Soneira. After accounting for the direct effect of the large-scale structure on overline{z}(m), we can then search for peculiar velocities. Taking all three regions into consideration, the data reject at the ≈4σ level the idea that we have recovered the cosmic microwave background rest frame in the volume probed. We therefore conclude that there is some consistent evidence from both counts and Hubble diagrams for a local hole' with an ≈150 h-1 Mpc underdensity that deeper counts and redshifts in the northern Galactic cap suggest may extend to ≈300 h-1 Mpc.

14. The discovery of seven extremely low surface brightness galaxies in the field of the nearby spiral galaxy M101

Merritt, Allison; Abraham, Roberto

2014-01-01

Dwarf satellite galaxies are a key probe of dark matter and of galaxy formation on small scales and of the dark matter halo masses of their central galaxies. They have very low surface brightness, which makes it difficult to identify and study them outside of the Local Group. We used a low surface brightness-optimized telescope, the Dragonfly Telephoto Array, to search for dwarf galaxies in the field of the massive spiral galaxy M101. We identify seven large, low surface brightness objects in this field, with effective radii of \$$10 - 30\$$ arcseconds and central surface brightnesses of \$$\\mu_{g} \\sim 25.5 - 27.5\$$ mag arcsec\$$^{-2}\$$. Given their large apparent sizes and low surface brightnesses, these objects would likely be missed by standard galaxy searches in deep fields. Assuming the galaxies are dwarf satellites of M101, their absolute magnitudes are in the range \$$-11.6 \\lesssim M_{V} \\lesssim -9.3\$$ and their effective radii are \$$350\$$ pc \$$-\$$ \$$1.3\$$ kpc. Their radial surface brightness profiles ar...

15. Deep Galex Observations of the Coma Cluster: Source Catalog and Galaxy Counts

Hammer, D.; Hornschemeier, A. E.; Mobasher, B.; Miller, N.; Smith, R.; Arnouts, S.; Milliard, B.; Jenkins, L.

2010-01-01

We present a source catalog from deep 26 ks GALEX observations of the Coma cluster in the far-UV (FUV; 1530 Angstroms) and near-UV (NUV; 2310 Angstroms) wavebands. The observed field is centered 0.9 deg. (1.6 Mpc) south-west of the Coma core, and has full optical photometric coverage by SDSS and spectroscopic coverage to r-21. The catalog consists of 9700 galaxies with GALEX and SDSS photometry, including 242 spectroscopically-confirmed Coma member galaxies that range from giant spirals and elliptical galaxies to dwarf irregular and early-type galaxies. The full multi-wavelength catalog (cluster plus background galaxies) is 80% complete to NUV=23 and FUV=23.5, and has a limiting depth at NUV=24.5 and FUV=25.0 which corresponds to a star formation rate of 10(exp -3) solar mass yr(sup -1) at the distance of Coma. The GALEX images presented here are very deep and include detections of many resolved cluster members superposed on a dense field of unresolved background galaxies. This required a two-fold approach to generating a source catalog: we used a Bayesian deblending algorithm to measure faint and compact sources (using SDSS coordinates as a position prior), and used the GALEX pipeline catalog for bright and/or extended objects. We performed simulations to assess the importance of systematic effects (e.g. object blends, source confusion, Eddington Bias) that influence source detection and photometry when using both methods. The Bayesian deblending method roughly doubles the number of source detections and provides reliable photometry to a few magnitudes deeper than the GALEX pipeline catalog. This method is also free from source confusion over the UV magnitude range studied here: conversely, we estimate that the GALEX pipeline catalogs are confusion limited at NUV approximately 23 and FUV approximately 24. We have measured the total UV galaxy counts using our catalog and report a 50% excess of counts across FUV=22-23.5 and NUV=21.5-23 relative to previous GALEX

16. The Local Hole revealed by galaxy counts and redshifts

Whitbourn, J R

2013-01-01

The redshifts of ~250000 galaxies are used to study the Local Hole and its associated peculiar velocities. The sample, compiled from 6dFGS and SDSS provides wide sky coverage to a depth of ~300h-1Mpc. We have therefore examined K and r limited galaxy redshift distributions and number counts to map the local density field. Comparing observed galaxy n(z) distributions to homogeneous models in three large regions of the high latitude sky, we find evidence for under-densities ranging from ~4-40% in these regions to depths of ~150h-1Mpc with the deepest under-density being over the Southern Galactic cap. Using the Galaxy and Mass Assembly (GAMA) survey we then establish the normalisation of galaxy counts at fainter magnitudes and thus confirm that the underdensity over all three fields at K<12.5 is ~15+-3%. Finally, we further use redshift catalogues to map peculiar velocities over the same areas using the average redshift - magnitude, zbar(m), technique of Soneira (1979). After accounting for the direct effect...

17. Measuring Distances and Probing the Unresolved Stellar Populations of Galaxies Using Infrared Surface Brightness Fluctuations

Jensen, Joseph B.; Tonry, John L.; Barris, Brian J.; Thompson, Rodger I.; Liu, Michael C.; Rieke, Marcia J.; Ajhar, Edward A.; Blakeslee, John P

2002-01-01

To empirically calibrate the IR surface brightness fluctuation (SBF) distance scale and probe the properties of unresolved stellar populations, we measured fluctuations in 65 galaxies using NICMOS on the Hubble Space Telescope. The early-type galaxies in this sample include elliptical and S0 galaxies and spiral bulges in a variety of environments. Absolute fluctuation magnitudes in the F160W (1.6 micron) filter were derived for each galaxy using previously-measured I-band SBF and Cepheid vari...

18. Unveiling the nature of bright z ~ 7 galaxies with the Hubble Space Telescope

Bowler, R A A; McLure, R J; McLeod, D J

2016-01-01

We present new Hubble Space Telescope/Wide Field Camera 3 imaging of 25 extremely luminous (-23.2 600A). We find that irregular, multiple-component morphologies suggestive of clumpy or merging systems are common (f_multi > 0.4) in bright z ~ 7 galaxies, and ubiquitous at the very bright end (M_UV 1000 similarly bright galaxies at z ~ 7. Our new HST imaging suggests that the vast majority of these galaxies will be spatially resolved by Euclid, mitigating concerns over dwarf star contamination.

19. A large sample of low surface brightness disc galaxies from the SDSS- II. Metallicities in surface brightness bins

Liang, Y C; Hammer, F; Chen, X Y; Liu, F S; Gao, D; Hu, J Y; Deng, L C; Zhang, B

2010-01-01

We study the spectroscopic properties of a large sample of Low Surface Brightness galaxies (LSBGs) (with B-band central surface brightness mu0(B)>22 mag arcsec^(-2)) selected from the Sloan Digital Sky Survey Data Release 4 (SDSS-DR4) main galaxy sample. A large sample of disk-dominated High Surface Brightness galaxies (HSBGs, with mu0(B)<22 mag arcsec^(-2)) are also selected for comparison simultaneously. To study them in more details, these sample galaxies are further divided into four subgroups according to mu0(B) (in units of mag arcsec^(-2)): vLSBGs (24.5-22.75),iLSBGs (22.75-22.0), iHSBGs (22.0-21.25), and vHSBGs (<21.25). The diagnostic diagram from spectral emission-line ratios shows that the AGN fractions of all the four subgroups are small (<9%). The 21,032 star-forming galaxies with good quality spectroscopic observations are further selected for studying their dust extinction, strong-line ratios, metallicities and stellar mass-metallicities relations. The vLSBGs have lower extinction valu...

20. The visibility of galaxies as a function of central surface brightness

The likelihood of a galaxy with given intrinsic profile appearing in a photograph catalogue with limiting criteria on apparent magnitude and angular size will depend on the maximum distance at which such a galaxy can lie and still obey both criteria. It is demonstrated that the corresponding volume in which the galaxy will be visible is a sensitive function of the galaxy's central surface brightness as well as its absolute magnitude. Before the observed concentrations around preferred values of surface brightness can be regarded as real, it will be necessary to make allowance for this selection effect. (author)

1. DGSAT: Dwarf Galaxy Survey with Amateur Telescopes. I. Discovery of low surface brightness systems around nearby spiral galaxies

Javanmardi, B.; Martinez-Delgado, D.; Kroupa, P.; Henkel, C.; Crawford, K.; Teuwen, K.; Gabany, R. J.; Hanson, M.; Chonis, T. S.; Neyer, F.

2016-04-01

Context. We introduce the Dwarf Galaxy Survey with Amateur Telescopes (DGSAT) project and report the discovery of eleven low surface brightness (LSB) galaxies in the fields of the nearby galaxies NGC 2683, NGC 3628, NGC 4594 (M 104), NGC 4631, NGC 5457 (M 101), and NGC 7814. Aims: The DGSAT project aims to use the potential of small-sized telescopes to probe LSB features around large galaxies and to increase the sample size of the dwarf satellite galaxies in the Local Volume. Methods: Using long exposure images, fields of the target spiral galaxies are explored for extended LSB objects. After identifying dwarf galaxy candidates, their observed properties are extracted by fitting models to their light profiles. Results: We find three, one, three, one, one, and two new LSB galaxies in the fields of NGC 2683, 3628, 4594, 4631, 5457, and 7814, respectively. In addition to the newly found galaxies, we analyse the structural properties of nine already known galaxies. All of these 20 dwarf galaxy candidates have effective surface brightnesses in the range 25.3 ≲ μe ≲ 28.8 mag arcsec-2 and are fit with Sersic profiles with indices n ≲ 1. Assuming that they are in the vicinity of the above mentioned massive galaxies, their r-band absolute magnitudes, their effective radii, and their luminosities are in the ranges -15.6 ≲ Mr ≲ -7.8, 160 pc ≲ Re ≲ 4.1 kpc, and 0.1 × 106 ≲ (L/L⊙)r ≲ 127 × 106, respectively. To determine whether these LSB galaxies are indeed satellites of the above mentioned massive galaxies, their distances need to be determined via further observations. Conclusions: Using small telescopes, we are readily able to detect LSB galaxies with similar properties to the known dwarf galaxies of the Local Group.

2. Properties of Submillimeter Galaxies in a Semi-analytic Model using the "Count Matching" Approach: Application to the ECDF-S

Arancibia, Alejandra M Muñoz; Padilla, Nelson D; Cora, Sofía A; Gawiser, Eric; Kurczynski, Peter L; Ruiz, Andrés N

2014-01-01

We present a new technique for modeling submillimeter galaxies (SMGs): the "Count Matching" approach. Using lightcones drawn from a semi-analytic model of galaxy formation, we choose physical galaxy properties given by the model as proxies for their submillimeter luminosities, assuming a monotonic relationship. As recent interferometric observations of the Extended Chandra Deep Field South show that the brightest sources detected by single-dish telescopes are comprised by emission from multiple fainter sources, we assign the submillimeter fluxes so that the combined LABOCA plus bright-end ALMA observed number counts for this field are reproduced. After turning the model catalogs given by the proxies into submillimeter maps, we perform a source extraction to include the effects of the observational process on the recovered counts and galaxy properties. We find that for all proxies, there are lines of sight giving counts consistent with those derived from LABOCA observations, even for input sources with randomi...

3. Musings concerning the possible significance of surface brightness variations in disk galaxies

The implications of the surface-brightness (SB) distribution of observed disk galaxies are explored, reviewing the results of recent investigations. Topics addressed include the SBs of catalog galaxies, proper measurements of SB, searches for new low-SB objects, and the importance of low-SB galaxies rich in H I for theoretical models of star formation. Key theoretical questions are listed, and tentative answers are given along with recommendations for further observations. 30 references

4. Spatial distributions of core-collapse supernovae in infrared-bright galaxies

Kangas, Tuomas; Kankare, Erkki; Kotilainen, Jari K; Väisänen, P; Greimel, R; Takalo, A

2013-01-01

We have measured the correlation between the locations of core-collapse supernovae (CCSNe) and host galaxy light in the Ha line, near ultraviolet (NUV), R-band and Ks-band to constrain the progenitors of CCSNe using pixel statistics. Our sample consists of 86 CCSNe in 57 infrared (IR)-bright galaxies, of which many are starbursts and ten are luminous infrared galaxies (LIRGs). We also analyse the radial distribution of CCSNe in these galaxies, and determine power-law and exponential fits to CCSN surface density profiles. To probe differences between the SNe of these galaxies and normal spiral galaxies, our results were compared to previous studies with samples dominated by normal spiral galaxies where possible. We obtained a normalised scale length of 0.23^{+0.03}_{-0.02} R_25 for the CCSN surface density in IR-bright galaxies; less than that derived for CCSNe in a sample dominated by normal spiral galaxies (0.29 \\pm 0.01). This reflects a more centrally concentrated population of massive stars in IR-bright g...

5. AXIAL RATIO OF EDGE-ON SPIRAL GALAXIES AS A TEST FOR BRIGHT RADIO HALOS

Singal, J.; Jones, E.; Dunlap, H. [Physics Department, University of Richmond 28 Westhampton Way, Richmond, VA 23173 (United States); Kogut, A., E-mail: jsingal@richmond.edu [Code 665, NASA Goddard Space Flight Center Greenbelt, MD 20771 (United States)

2015-01-20

We use surface brightness contour maps of nearby edge-on spiral galaxies to determine whether extended bright radio halos are common. In particular, we test a recent model of the spatial structure of the diffuse radio continuum by Subrahmanyan and Cowsik which posits that a substantial fraction of the observed high-latitude surface brightness originates from an extended Galactic halo of uniform emissivity. Measurements of the axial ratio of emission contours within a sample of normal spiral galaxies at 1500 MHz and below show no evidence for such a bright, extended radio halo. Either the Galaxy is atypical compared to nearby quiescent spirals or the bulk of the observed high-latitude emission does not originate from this type of extended halo. (letters)

6. TESTING MODIFIED NEWTONIAN DYNAMICS WITH ROTATION CURVES OF DWARF AND LOW SURFACE BRIGHTNESS GALAXIES

Dwarf and low surface brightness (LSB) galaxies are ideal objects to test modified Newtonian dynamics (MOND), because in most of these galaxies the accelerations fall below the threshold where MOND supposedly applies. We have selected from the literature a sample of 27 dwarf and LSB galaxies. MOND is successful in explaining the general shape of the observed rotation curves for roughly three quarters of the galaxies in the sample presented here. However, for the remaining quarter, MOND does not adequately explain the observed rotation curves. Considering the uncertainties in distances and inclinations for the galaxies in our sample, a small fraction of poor MOND predictions is expected and is not necessarily a problem for MOND. We have also made fits taking the MOND acceleration constant, a 0, as a free parameter in order to identify any systematic trends. We find that there appears to be a correlation between central surface brightness and the best-fit value of a0, in the sense that lower surface brightness galaxies tend to have lower a0. However, this correlation depends strongly on a small number of galaxies whose rotation curves might be uncertain due to either bars or warps. Without these galaxies, there is less evidence of a trend, but the average value we find for a0 ∼ 0.7 x 10-8 cm s-2 is somewhat lower than derived from previous studies. Such lower fitted values of a0 could occur if external gravitational fields are important.

7. Galaxy And Mass Assembly (GAMA): detection of low-surface-brightness galaxies from SDSS data

Williams, R P; Kelvin, L S; James, P A; Driver, S P; Prescott, M; Brough, S; Brown, M J I; Davies, L J M; Holwerda, B W; Liske, J; Norberg, P; Moffett, A J; Wright, A H

2016-01-01

We report on a search for new low-surface-brightness galaxies (LSBGs) using Sloan Digital Sky Survey (SDSS) data within the GAMA equatorial fields. The search method consisted of masking objects detected with SDSS photo, combining gri images weighted to maximise the expected signal-to-noise ratio (SNR), and smoothing the images. The processed images were then run through a detection algorithm that finds all pixels above a set threshold and groups them based on their proximity to one another. The list of detections was cleaned of contaminants such as diffraction spikes and the faint wings of masked objects. From these, selecting potentially the brightest in terms of total flux, a list of 343 LSBGs was produced having been confirmed using VISTA Kilo-degree Infrared Galaxy Survey (VIKING) imaging. The photometry of this sample was refined using the deeper VIKING Z band as the aperture-defining band. Measuring their $g-i$ and $J-K$ colours shows that most are consistent with being at redshifts less than 0.2. The ...

8. Near-Infrared Imaging of Barred Halo Dominated Low Surface Brightness Galaxies

Honey, M.; Das, M.; Ninan, J. P.; Purvankara, M.

2016-01-01

We present a near-infrared (NIR) imaging study of barred low surface brightness (LSB) galaxies using the TIFR near-infrared Spectrometer and Imager (TIRSPEC). LSB galaxies are dark matter dominated, late type spirals that have low luminosity stellar disks but large neutral hydrogen (HI) gas disks. Using SDSS images of a very large sample of LSB galaxies derived from the literature, we found that the barred fraction is only 8.3%. We imaged twenty five barred LSB galaxies in the J, H, K$_S$ wav...

9. An Increasing Stellar Baryon Fraction in Bright Galaxies at High Redshift

Finkelstein, Steven L; Behroozi, Peter; Somerville, Rachel S; Papovich, Casey; Milosavljevic, Milos; Dekel, Avishai; Narayanan, Desika; Ashby, Matthew L N; Cooray, Asantha; Fazio, Giovanni G; Ferguson, Henry C; Koekemoer, Anton M; Salmon, Brett W; Willner, S P

2015-01-01

Recent observations have shown that the characteristic luminosity of the rest-frame ultraviolet (UV) luminosity function does not significantly evolve at 4 < z < 7 and is approximately M*_UV ~ -21. We investigate this apparent non-evolution by examining a sample of 190 bright, M_UV < -21 galaxies at z=4 to 7, analyzing their stellar populations and host halo masses. Including deep Spitzer/IRAC imaging to constrain the rest-frame optical light, we find that M*_UV galaxies at z=4-7 have similar stellar masses of log(M/Msol)=9.8-9.9 and are thus relatively massive for these high redshifts. However, bright galaxies at z=4-7 are less massive and have younger inferred ages than similarly bright galaxies at z=2-3, even though the two populations have similar star formation rates and levels of dust attenuation. We match the abundances of these bright z=4-7 galaxies to halo mass functions from the Bolshoi Lambda-CDM simulation to estimate the halo masses. We find that the typical halo masses in ~M*_UV galaxie...

10. The Effect of Nearby Voids on Galaxy Number Counts

Bucklein, Brian K; Hintz, Eric G

2016-01-01

The size, shape and degree of emptiness of void interiors sheds light on the details of galaxy formation. A particularly interesting question is whether void interiors are completely empty or contain a dwarf population. However the nearby voids that are most conducive for dwarf searches have large angular diameters, on the order of a steradian, making it difficult to redshift-map a statistically significant portion of their volume to the magnitude limit of dwarf galaxies. As part of addressing this problem, we investigate here the usefulness of number counts in establishing the best locations to search inside nearby (d < 300 Mpc) galaxy voids, utilizing Wolf plots of log(n < m) vs. m as the basic diagnostic. To illustrate expected signatures, we consider the signature of three void profiles, "cut out", "built up", and "universal profile" carved into Monte-Carlo Schechter function models. We then investigate the signatures of voids in the Millennium Run dark matter simulation and the Sloan Digital Sky Su...

11. Short time-scale variability in bright Seyfert galaxies

High-quality, long-slit CCD spectroscopic data were obtained to search for short time-scale (hour-day) variability in a sample of five Seyfert galaxies. The equivalent widths of all of the emission lines and the relative intensities of the Balmer lines were measured for each galaxy. No significant profile or flux variations were observed for any galaxy within errors, except for NGC 4151. The broad-line flux variation in NGC 4151 is attributed to continuum fluctuations. 21 refs

12. Short time-scale variability in bright Seyfert galaxies

Xanthopoulos, E.; De robertis, M.M. (York University, Toronto (Canada))

1991-04-01

High-quality, long-slit CCD spectroscopic data were obtained to search for short time-scale (hour-day) variability in a sample of five Seyfert galaxies. The equivalent widths of all of the emission lines and the relative intensities of the Balmer lines were measured for each galaxy. No significant profile or flux variations were observed for any galaxy within errors, except for NGC 4151. The broad-line flux variation in NGC 4151 is attributed to continuum fluctuations. 21 refs.

13. Surface Brightness Profiles and Star Formation Rates of Galaxies in NRGb054

Hansen, Ellen; Koopmann, Rebecca A.; Miller, Brendan; Durbala, Adriana; Fitzgerald, Garrett

2016-01-01

We present new optical R and H-alpha images of the galaxy group NRGb054, obtained with the WIYN 0.9m telescope at KPNO using the MOSAIC camera. This group was studied as part of the larger Undergraduate ALFALFA Team project investigating the effects of a group environment on star formation. The stacked H-alpha image was continuum subtracted by the removal of a scaled and stacked R image. Surface photometry was performed on R and continuum-subtracted H-alpha cutouts of 20 covered galaxies to determine the surface brightness as a function of radius. Integrating the continuum-subtracted H-alpha surface brightness profile provides the total star formation within that galaxy, while the shape of the profile illustrates how star formation is spread throughout the galaxy. We provide a catalog of surface brightness profiles and integrated star formation rates for NRGb054. We consider star formation as a function of galaxy-galaxy separation and galaxy location within the group, and discuss our findings in the context of the wider study. This work has been supported by NSF grant AST-1211005.

14. Long term optical variability of bright X-ray point sources in elliptical galaxies

We present long term optical variability studies of bright X-ray sources in four nearby elliptical galaxies with the Chandra Advanced CCD Imaging Spectrometer array (ACIS-S) and observations from the Hubble Space Telescope (HST) Advanced Camera for Surveys. Out of the 46 bright (X-ray counts > 60) sources that are in the common field of view of the Chandra and HST observations, 34 of them have potential optical counterparts, while the rest of them are optically dark. After taking into account systematic errors, estimated using optical sources in the field as a reference, we find that four of the X-ray sources (three in NGC 1399 and one in NGC 1427) have variable optical counterparts at a high level of significance. The X-ray luminosities of these sources are ∼ 1038 erg s−1 and are also variable on similar time scales. The optical variability implies that the optical emission is associated with the X-ray source itself rather than being the integrated light from a host globular cluster. For one source, the change in optical magnitude is > 0.3, which is one of the highest reported for this class of X-ray sources and this suggests that the optical variability is induced by the X-ray activity. However, the optically variable sources in NGC 1399 have been reported to have blue colors (g — z > 1). All four sources have been detected in the infrared (IR) by Spitzer as point sources, and their ratios of 5.8 to 3.6 μm flux are > 0.63, indicating that their IR spectra are like those of Active Galactic Nuclei (AGNs). While spectroscopic confirmation is required, it is likely that all four sources are background AGNs. We find none of the X-ray sources having optical/IR colors different from AGNs to be optically variable

15. High-resolution rotation curves of low surface brightness galaxies Data

McGaugh, S S; De Blok, E; Gaugh, Stacy Mc; Rubin, Vera; Blok, Erwin de

2001-01-01

We present long slit Halpha observations of 50 low surface brightness galaxies. Of these, 36 are of sufficient quality to form rotation curves. These data provide a large increase in the number of low surface brightness galaxies for which accurate rotation curves are available. They also represent an order of magnitude improvement in spatial resolution over previous 21 cm studies (1" to 2" instead of 13" to 45"). The improved resolution and accuracy of the data extend and strengthen the scientific conclusions previously inferred from 21 cm data.

16. On the Classification of UGC1382 as a Giant Low Surface Brightness Galaxy

Hagen, Lea M Z; Hagen, Alex; Nyland, Kristina; Neill, James D; Treyer, Marie; Young, Lisa M; Rich, Jeffrey A; Madore, Barry F

2016-01-01

We provide evidence that UGC1382, long believed to be a passive elliptical galaxy, is actually a giant low surface brightness (GLSB) galaxy which rivals the archetypical GLSB Malin 1 in size. Like other GLSB galaxies, it has two components: a high surface brightness disk galaxy surrounded by an extended low surface brightness (LSB) disk. For UGC1382, the central component is a lenticular system with an effective radius of 6 kpc. Beyond this, the LSB disk has an effective radius of ~38 kpc and an extrapolated central surface brightness of ~26 mag/arcsec^2. Both components have a combined stellar mass of ~8x10^10 M_sun, and are embedded in a massive (10^10 M_sun) low-density (<3 M_sun/pc^2) HI disk with a radius of 110 kpc, making this one of the largest isolated disk galaxies known. The system resides in a massive dark matter halo of at least 2x10^12 M_sun. Although possibly part of a small group, its low density environment likely plays a role in the formation and retention of the giant LSB and HI disks. W...

17. Chemical abundances in low surface brightness galaxies: Implications for their evolution

Mcgaugh, S. S.; Bothun, G. D.

1993-01-01

Low Surface Brightness (LSB) galaxies are an important but often neglected part of the galaxy content of the universe. Their importance stems both from the selection effects which cause them to be under-represented in galaxy catalogs, and from what they can tell us about the physical processes of galaxy evolution that has resulted in something other than the traditional Hubble sequence of spirals. An important constraint for any evolutionary model is the present day chemical abundances of LSB disks. Towards this end, spectra for a sample of 75 H 2 regions distributed in 20 LSB disks galaxies were obtained. Structurally, this sample is defined as having B(0) fainter than 23.0 mag arcsec(sup -2) and scale lengths that cluster either around 3 kpc or 10 kpc. In fact, structurally, these galaxies are very similar to the high surface brightness spirals which define the Hubble sequence. Thus, our sample galaxies are not dwarf galaxies but instead have masses comparable to or in excess of the Milky Way. The basic results from these observations are summarized.

18. The Effect of Surface Brightness Dimming in the Selection of High-z Galaxies

Calvi, Valentina; Bradley, Larry; Pizzella, Alessandro; Kim, Soyoung

2014-01-01

Cosmological surface brightness dimming of the form $(1+z)^{-4}$ affects all sources. The strong dependence of surface brightness dimming on redshift z suggests the presence of a selection bias when searching for high-redshift galaxies, i.e. we tend to detect only those galaxies with a high surface brightness (SB). However, unresolved knots of emission are not affected by SB dimming, thus providing a way to test the clumpiness of high-z galaxies. Our strategy relies on the comparison of the total flux detected for the same source in surveys characterized by different depth. For all galaxies, deeper images permit the better investigation of low-SB features. Cosmological SB dimming makes these low-SB features hard to detect when going to higher and higher redshifts. We used the GOODS and HUDF Hubble Space Telescope legacy datasets to study the effect of SB dimming on low-SB features of high-redshift galaxies and compare it to the prediction for smooth sources. We selected a sample of Lyman-break galaxies at z~4...

19. The SWIFT AGN and Cluster Survey I: Number Counts of AGN and Galaxy Clusters

Dai, Xinyu; Kochanek, Christopher S; Nugent, Jenna M; Bregman, Joel N

2015-01-01

The Swift AGN and Cluster Survey (SACS) uses 125 deg^2 of Swift XRT serendipitous fields with variable depths surrounding gamma-ray bursts to provide a medium depth (4e-15 erg/s/cm^2) and area survey filling the gap between deep, narrow Chandra/XMM-Newton surveys and wide, shallow ROSAT surveys. Here we present a catalog of 22,563 point sources and 442 extended sources and examine the number counts of the AGN and galaxy cluster populations. SACS provides excellent constraints on the AGN number counts at the bright end with negligible uncertainties due to cosmic variance, and these constraints are consistent with previous measurements. We use Wise mid-infrared (MIR) colors to classify the sources. For AGN we can roughly separate the point sources into MIR-red and MIR-blue AGN, finding roughly equal numbers of each type in the soft X-ray band (0.5-2 keV), but fewer MIR-blue sources in the hard X-ray band (2-8 keV). The cluster number counts, with 5% uncertainties from cosmic variance, are also consistent with p...

20. A 5-GHz survey of bright southern elliptical and SO galaxies

The Parkes 64-m telescope has been used in a 5.0 GHz survey of 181 Southern E and SO galaxies from the Reference catalogue of bright galaxies. Of the 39 detections above the nominal limit of 12 mJy, 15 are new, several have radio spectra indicating membership in the active class, and two have shown intensity variations at centimetre wavelengths. The results of this survey combined with results from earlier surveys of lower sensitivity suggest that only about 40 per cent of the E/SO galaxies in the Reference catalogue have Ssub(5GHz)>1 mJy. (author)

1. Bulge-Disk Decomposition of 659 Spiral and Lenticular Galaxy Brightness Profiles

Baggett, W. E.; Baggett, S. M.; Anderson, K. S. J.

1998-01-01

We present one of the largest homogeneous sets of spiral and lenticular galaxy brightness profile decompositions completed to date. The 659 galaxies in our sample have been fitted with a deVaucouleurs' law for the bulge component and an inner-truncated exponential for the disk component. Of the 659 galaxies in the sample, 620 were successfully fit with the chosen fitting functions. The fits are generally well-defined, with more than 90% having RMS deviations from the observed profile of less ...

2. Near-Infrared Imaging of Barred Halo Dominated Low Surface Brightness Galaxies

Honey, M; Ninan, J P; Purvankara, M

2016-01-01

We present a near-infrared (NIR) imaging study of barred low surface brightness (LSB) galaxies using the TIFR near-infrared Spectrometer and Imager (TIRSPEC). LSB galaxies are dark matter dominated, late type spirals that have low luminosity stellar disks but large neutral hydrogen (HI) gas disks. Using SDSS images of a very large sample of LSB galaxies derived from the literature, we found that the barred fraction is only 8.3%. We imaged twenty five barred LSB galaxies in the J, H, K$_S$ wavebands and twenty nine in the K$_S$ band. Most of the bars are much brighter than their stellar disks, which appear to be very diffuse. Our image analysis gives deprojected mean bar sizes of $R_{b}/R_{25}$ = 0.40 and ellipticities $e$ $\\approx$ 0.45, which are similar to bars in high surface brightness galaxies. Thus, although bars are rare in LSB galaxies, they appear to be just as strong as bars found in normal galaxies. There is no correlation of $R_{b}/R_{25}$ or $e$ with the relative HI or stellar masses of the galax...

3. The IRAS bright galaxy sample. II - The sample and luminosity function

Soifer, B. T.; Sanders, D. B.; Neugebauer, G.; Madore, B. F.; Danielson, G. E.

1987-01-01

A statistically complete sample of 324 of the brightest infrared galaxies discovered at 60 microns in the IRAS all-sky survey is described. The results show that far-infrared emission is a significant luminosity component in the local universe, representing 25 percent of the luminosity emitted by stars in the same volume. Above 10 to the 11th solar luminosities, the infrared luminous galaxies are the dominant population of objects in the universe, being as numerous as the Seyfert galaxies and more numerous than quasars at higher luminosities. The infrared luminosity appears to be independent of the optical luminosity of galaxies. Most infrared bright galaxies appear to require much of the interstellar matter to be contributing to the observed infrared luminosity. Approximately 60-80 percent of the far-infrared luminosity of the local universe can be attributed, directly or indirectly, to recent or ongoing star formation.

4. Is there really a luminosity-surface brightness relation for dwarf galaxies?

A simple test is used to argue that the luminosity-surface brightness correlation found by several authors in eye-selected samples of cluster dwarf galaxies is likely to be merely the result of selection effects. There are therefore likely to be many more dwarfs in clusters like Virgo than is generally assumed. (author)

5. The formation of submillimetre-bright galaxies from gas infall over a billion years.

Narayanan, Desika; Turk, Matthew; Feldmann, Robert; Robitaille, Thomas; Hopkins, Philip; Thompson, Robert; Hayward, Christopher; Ball, David; Faucher-Giguère, Claude-André; Kereš, Dušan

2015-09-24

Submillimetre-bright galaxies at high redshift are the most luminous, heavily star-forming galaxies in the Universe and are characterized by prodigious emission in the far-infrared, with a flux of at least five millijanskys at a wavelength of 850 micrometres. They reside in haloes with masses about 10(13) times that of the Sun, have low gas fractions compared to main-sequence disks at a comparable redshift, trace complex environments and are not easily observable at optical wavelengths. Their physical origin remains unclear. Simulations have been able to form galaxies with the requisite luminosities, but have otherwise been unable to simultaneously match the stellar masses, star formation rates, gas fractions and environments. Here we report a cosmological hydrodynamic galaxy formation simulation that is able to form a submillimetre galaxy that simultaneously satisfies the broad range of observed physical constraints. We find that groups of galaxies residing in massive dark matter haloes have increasing rates of star formation that peak at collective rates of about 500-1,000 solar masses per year at redshifts of two to three, by which time the interstellar medium is sufficiently enriched with metals that the region may be observed as a submillimetre-selected system. The intense star formation rates are fuelled in part by the infall of a reservoir gas supply enabled by stellar feedback at earlier times, not through major mergers. With a lifetime of nearly a billion years, our simulations show that the submillimetre-bright phase of high-redshift galaxies is prolonged and associated with significant mass buildup in early-Universe proto-clusters, and that many submillimetre-bright galaxies are composed of numerous unresolved components (for which there is some observational evidence). PMID:26399829

6. RED GIANT BRANCH BUMP BRIGHTNESS AND NUMBER COUNTS IN 72 GALACTIC GLOBULAR CLUSTERS OBSERVED WITH THE HUBBLE SPACE TELESCOPE

We present the broadest and most precise empirical investigation of red giant branch bump (RGBB) brightness and number counts ever conducted. We implement a new method and use data from two Hubble Space Telescope globular cluster (GC) surveys to measure the brightness and star counts of the RGBB in 72 GCs. The median measurement precision is 0.018 mag in the brightness and 31% in the number counts, respectively, reaching peak precision values of 0.005 mag and 10%. The position of the main-sequence turnoff and the number of horizontal branch stars are used as comparisons where appropriate. Several independent scientific conclusions are newly possible with our parameterization of the RGBB. Both brightness and number counts are shown to have second parameters in addition to their strong dependence on metallicity. The RGBBs are found to be anomalous in the GCs NGC 2808, 5286, 6388, and 6441, likely due to the presence of multiple populations. Finally, we use our empirical calibration to predict the properties of the Galactic bulge RGBB. The updated RGBB properties for the bulge are shown to differ from the GC-calibrated prediction, with the former having lower number counts, a lower brightness dispersion, and a brighter peak luminosity than would be expected from the latter. This discrepancy is well explained by the Galactic bulge having a higher helium abundance than expected from GCs, ΔY ∼ +0.06 at the median metallicity.

7. X-Ray bright active galactic nuclei in massive galaxy clusters - II. The fraction of galaxies hosting active nuclei

Ehlert, S.; von der Linden, A.; Allen, S. W.;

2013-01-01

We present a measurement of the fraction of cluster galaxies hosting X-ray bright active galactic nuclei (AGN) as a function of clustercentric distance scaled in units of r500. Our analysis employs high-quality Chandra X-ray and Subaru optical imaging for 42 massive X-ray-selected galaxy cluster...... fields spanning the redshift range 0.2 z ..., both of which are also suppressed near cluster centres to a comparable extent. These results strongly support the idea that X-ray AGN activity and strong star formation are linked through their common dependence on available reservoirs of cold gas. © 2013 The Authors. Published by Oxford University...

8. Damped Lyman-alpha absorption from a nearby Low Surface Brightness galaxy

Bowen, D V

2001-01-01

Ground-based & HST images of the nearby galaxy SBS 1543+593 (z=0.009) show it to be a Low Surface Brightness (LSB) galaxy with a central surface brightness of mu_B(0)=23.2 mag/arcsec-2 and scale length 0.9 h-1 kpc, values typical for the local LSB galaxy population. The galaxy lies directly in front of the QSO HS 1543+5921 (z=0.807); an HST STIS spectrum of the quasar reveals a damped Lyman-alpha (DLA) line at the redshift of the interloper with an HI column density of log N(HI) = 20.35, as well as several low-ionization metal lines with strengths similar to those found in the Milky Way interstellar medium. Our data show that LSB galaxies are certainly able to produce the DLA lines seen at higher redshift, and fuels the speculation that LSB galaxies are a major contributor to that population of absorbers.

9. HerMES: SPIRE galaxy number counts at 250, 350 and 500 microns

Oliver, S J; Smith, A J; Altieri, B; Amblard, A; Arumugam, V; Auld, R; Aussel, H; Babbedge, T; Blain, A; Bock, J; Boselli, A; Buat, V; Burgarella, D; Castro-Rodriguez, N; Cava, A; Chanial, P; Clements, D L; Conley, A; Conversi, L; Cooray, A; Dowell, C D; Dwek, E; Eales, S; Elbaz, D; Fox, M; Franceschini, A; Gear, W; Glenn, J; Griffin, M; Halpern, M; Hatziminaoglou, E; Ibar, E; Isaak, K; Ivison, R J; Lagache, G; Levenson, L; Lu, N; Madden, S; Maffei, B; Mainetti, G; Marchetti, L; Mitchell-Wynne, K; Mortier, A M J; Nguyen, H T; O'Halloran, B; Omont, A; Page, M J; Panuzzo, P; Papageorgiou, A; Pearson, C P; Perez-Fournon, I; Pohlen, M; Rawlings, J I; Raymond, G; Rigopoulou, D; Rizzo, D; Roseboom, I G; Rowan-Robinson, M; Portal, M Sanchez; Savage, R; Schulz, B; Scott, Douglas; Seymour, N; Shupe, D L; Stevens, J A; Symeonidis, M; Trichas, M; Tugwell, K E; Vaccari, M; Valiante, E; Valtchanov, I; Vieira, J D; Vigroux, L; Ward, R; Wright, G; Xu, C K; Zemcov, M

2010-01-01

Emission at far-infrared wavelengths makes up a significant fraction of the total light detected from galaxies over the age of Universe. Herschel provides an opportunity for studying galaxies at the peak wavelength of their emission. Our aim is to provide a benchmark for models of galaxy population evolution and to test pre-existing models of galaxies. With the Herschel Multi-tiered Extra-galactic survey, HerMES, we have observed a number of fields of different areas and sensitivity using the SPIRE instrument on Herschel. We have determined the number counts of galaxies down to ~20 mJy. Our constraints from directly counting galaxies are consistent with, though more precise than, estimates from the BLAST fluctuation analysis. We have found a steep rise in the Euclidean normalised counts at <100 mJy. We have directly resolved 15% of the infrared extra-galactic background at the wavelength near where it peaks.

10. The outer regions of galaxy clusters: Chandra constraints on the X-ray surface brightness

Ettori, S

2008-01-01

(Abridged version) We study the properties of the X-ray surface brightness profiles in a sample of galaxy clusters that are observed with Chandra and have emission detectable with a signal-to-noise ratio larger than 2 at a radius beyond R500 ~ 0.7 R200. Our study aims at measuring the slopes of the X-ray surface brightness and of the gas density profiles in the outskirts of massive clusters. These constraints are then compared to similar results obtained from observations and numerical simulations of the temperature and dark matter density profiles with the intention to present a consistent picture of the outer regions of galaxy clusters. We extract the surface brightness profiles S_b(r) from X-ray exposures obtained with Chandra of 52 X-ray luminous galaxy clusters at z>0.3. We estimate R200 both using a beta-model to reproduce the surface brightness profile and scaling relations from the literature, showing that the two methods converge to comparable values. We evaluate then the radius, R_S2N, at which the ...

11. Stellar Systems in the direction of the Hickson Compact Group 44 - I. Low Surface Brightness Galaxies

Castelli, A V Smith; Escudero, C G

2016-01-01

Context. In spite of the numerous studies of low-luminosity galaxies in different environments, there is still no consensus about their formation scenario. In particular, a large number of galaxies displaying extremely low-surface brightnesses have been detected in the last year, and the nature of these objects is under discussion. Aims. In this paper we report the detection of two extended low-surface brightness (LSB) objects (mueff_g'~27 mag) found, in projection, next to NGC 3193 and in the zone of the Hickson Compact Group (HCG) 44, respectively. Methods. We analyzed deep, high-quality, GEMINI-GMOS images with ELLIPSE within IRAF in order to obtain their brightness profiles and structural parameters. We also search for the presence of globular clusters (GC) in these fields. Results. We have found that, if these LSB galaxies were at the distances of NGC 3193 and HCG 44, they would show sizes and luminosities similar to those of the ultra-diffuse galaxies (UDGs) found in the Coma cluster and other associati...

12. Simulating a slow bar in the low surface brightness galaxy UGC 628

Chequers, Matthew H.; Spekkens, Kristine; Widrow, Lawrence M.; Gilhuly, Colleen

2016-08-01

We present a disc-halo N-body model of the low surface brightness galaxy UGC 628, one of the few systems that harbours a "slow" bar with a ratio of corotation radius to bar length of mathcal {R} equiv R_c/a_b ˜ 2. We select our initial conditions using SDSS DR10 photometry, a physically motivated radially variable mass-to-light ratio profile, and rotation curve data from the literature. A global bar instability grows in our submaximal disc model, and the disc morphology and dynamics agree broadly with the photometry and kinematics of UGC 628 at times between peak bar strength and the onset of buckling. Prior to bar formation, the disc and halo contribute roughly equally to the potential in the galaxy's inner region, giving the disc enough self gravity for bar modes to grow. After bar formation there is significant mass redistribution, creating a baryon dominated inner and dark matter dominated outer disc. This implies that, unlike most other low surface brightness galaxies, UGC 628 is not dark matter dominated everywhere. Our model nonetheless implies that UGC 628 falls on same the relationship between dark matter fraction and rotation velocity found for high surface brightness galaxies, and lends credence to the argument that the disc mass fraction measured at the location where its contribution to the potential peaks is not a reliable indicator of its dynamical importance at all radii.

13. The Distribution of Star Formation and Metals in the Low Surface Brightness Galaxy UGC 628

Young, J E; Wang, Sharon X

2015-01-01

We introduce the MUSCEL Program (MUltiwavelength observations of the Structure, Chemistry and Evolution of LSB galaxies), a project aimed at determining the star-formation histories of low surface brightness galaxies. MUSCEL utilizes ground-based optical spectra and space-based UV and IR photometry to fully constrain the star-formation histories of our targets with the aim of shedding light on the processes that led low surface brightness galaxies down a different evolutionary path from that followed by high surface brightness galaxies, such as our Milky Way. Here we present the spatially-resolved optical spectra of UGC 628, observed with the VIRUS-P IFU at the 2.7-m Harlen J. Smith Telescope at the McDonald Observatory, and utilize emission-line diagnostics to determine the rate and distribution of star formation as well as the gas-phase metallicity and metallicity gradient. We find highly clustered star formation throughout UGC 628, excluding the core regions, and a log(O/H) metallicity around -4.2, with mo...

14. BLACK HOLE MASS LIMITS FOR OPTICALLY DARK X-RAY BRIGHT SOURCES IN ELLIPTICAL GALAXIES

Estimation of the black hole mass in bright X-ray sources of nearby galaxies is crucial to the understanding of these systems and their formation. However, the present allowed black hole mass range spans five orders of magnitude (10 Msun 5 Msun) with the upper limit obtained from dynamical friction arguments. We show that the absence of a detectable optical counterpart for some of these sources can provide a much more stringent upper limit. The argument is based only on the assumption that the outer regions of their accretion disks are a standard one. Moreover, such optically dark X-ray sources cannot be foreground stars or background active galactic nuclei, and hence must be accreting systems residing within their host galaxies. As a demonstration we search for candidates among the point-like X-ray sources detected with Chandra in 13 nearby elliptical galaxies. We use a novel technique to search for faint optical counterparts in the Hubble Space Telescope images whereby we subtract the bright galaxy light based on isophotal modeling of the surface brightness. We show that for six sources with no detectable optical emission at the 3σ level, their black hole masses MBH sun. In particular, an ultra-luminous X-ray source in NGC 4486 has MBH sun. We discuss the potential of this method to provide stringent constraints on the black hole masses, and the implications on the physical nature of these sources.

15. A 21-cm line study of NGC 5963, an SC galaxy with a low-surface brightness disk

Bosma, A.; Athanassoula, E.; van der Hulst, J. M.

1988-06-01

Results are presented from a detailed 21-cm line study of the Sc galaxy NGC 5963. The extent of the H I emission is found to be roughly coincident with the optical image, the latter being of much lower surface brightness than normal for Sc galaxies. The velocity field shows little deviation from axial symmetry, and the derived rotation curve is typical for Sc galaxies about twice as bright as NGC 5963. A composite mass model is presented using the observed light distribution to calculate a rotation curve for the luminous part of the galaxy (assuming a constant M/L-ratio with radius); this calculated rotation curve is compared to the observed one to derive a rotation law for a dark halo. Comparison with Sc galaxies having normal disk surface brightnesses suggests that the halo in NGC 5963 is more concentrated than in normal Scs with similar rotation curves. The origin of the low surface brightness of the disk is discussed.

16. Stellar populations of bulges in galaxies with a low surface-brightness disc

Morelli, L.; Corsini, E. M.; Pizzella, A.; Dalla Bontà, E.; Coccato, L.; Méndez-Abreu, J.

2015-03-01

The radial profiles of the Hβ, Mg, and Fe line-strength indices are presented for a sample of eight spiral galaxies with a low surface-brightness stellar disc and a bulge. The correlations between the central values of the line-strength indices and velocity dispersion are consistent to those known for early-type galaxies and bulges of high surface-brightness galaxies. The age, metallicity, and α/Fe enhancement of the stellar populations in the bulge-dominated region are obtained using stellar population models with variable element abundance ratios. Almost all the sample bulges are characterized by a young stellar population, on-going star formation, and a solar α/Fe enhancement. Their metallicity spans from high to sub-solar values. No significant gradient in age and α/Fe enhancement is measured, whereas only in a few cases a negative metallicity gradient is found. These properties suggest that a pure dissipative collapse is not able to explain formation of all the sample bulges and that other phenomena, like mergers or acquisition events, need to be invoked. Such a picture is also supported by the lack of a correlation between the central value and gradient of the metallicity in bulges with very low metallicity. The stellar populations of the bulges hosted by low surface-brightness discs share many properties with those of high surface-brightness galaxies. Therefore, they are likely to have common formation scenarios and evolution histories. A strong interplay between bulges and discs is ruled out by the fact that in spite of being hosted by discs with extremely different properties, the bulges of low and high surface-brightness discs are remarkably similar.

17. Measurable relationship between bright galaxies and their faint companions in WHL J085910.0+294957, a galaxy cluster at z = 0.30: vestiges of infallen groups?

Lee, Joon Hyeop; Lee, Hye-Ran; Kim, Minjin; Seon, Kwang-Il; Kim, Sang Chul; Yang, Soung-Chul; Ree, Chang Hee; Lee, Jong Chul; Jeong, Hyunjin; Ko, Jongwan [Korea Astronomy and Space Science Institute, Daejeon 305-348 (Korea, Republic of); Choi, Changsu, E-mail: jhl@kasi.re.kr [CEOU/Astronomy Program, Department of Physics and Astronomy, Seoul National University, Seoul 151-742 (Korea, Republic of)

2014-08-20

The properties of satellite galaxies are closely related to their host galaxies in galaxy groups. In cluster environments, on the other hand, the interaction between close neighbors is known to be limited. Our goal is to examine the relationships between host and satellite galaxies in the harsh environment of a galaxy cluster. To achieve this goal, we study a galaxy cluster WHL J085910.0+294957 at z = 0.30 using deep images obtained with CQUEAN CCD camera mounted on the 2.1 m Otto Struve Telescope. After member selection based on the scaling relations of photometric and structural parameters, we investigate the relationship between bright (M{sub i} ≤ –18) galaxies and their faint (–18 < M{sub i} ≤ –15) companions. The weighted mean color of faint companion galaxies shows no significant dependence (<1σ to bootstrap uncertainties) on cluster-centric distance and local luminosity density as well as the luminosity and concentration of an adjacent bright galaxy. However, the weighted mean color shows marginal dependence (∼2.2σ) on the color of an adjacent bright galaxy when the sample is limited to bright galaxies with at least two faint companions. By using a permutation test, we confirm that the correlation in color between bright galaxies and their faint companions in this cluster is statistically significant with a confidence level of 98.7%. The statistical significance increases if we additionally remove non-members using the Sloan Digital Sky Survey photometric redshift information (∼2.6σ and 99.3%). Our results suggest three possible scenarios: (1) vestiges of infallen groups, (2) dwarf capturing, and (3) tidal tearing of bright galaxies.

18. Measurable relationship between bright galaxies and their faint companions in WHL J085910.0+294957, a galaxy cluster at z = 0.30: vestiges of infallen groups?

The properties of satellite galaxies are closely related to their host galaxies in galaxy groups. In cluster environments, on the other hand, the interaction between close neighbors is known to be limited. Our goal is to examine the relationships between host and satellite galaxies in the harsh environment of a galaxy cluster. To achieve this goal, we study a galaxy cluster WHL J085910.0+294957 at z = 0.30 using deep images obtained with CQUEAN CCD camera mounted on the 2.1 m Otto Struve Telescope. After member selection based on the scaling relations of photometric and structural parameters, we investigate the relationship between bright (Mi ≤ –18) galaxies and their faint (–18 < Mi ≤ –15) companions. The weighted mean color of faint companion galaxies shows no significant dependence (<1σ to bootstrap uncertainties) on cluster-centric distance and local luminosity density as well as the luminosity and concentration of an adjacent bright galaxy. However, the weighted mean color shows marginal dependence (∼2.2σ) on the color of an adjacent bright galaxy when the sample is limited to bright galaxies with at least two faint companions. By using a permutation test, we confirm that the correlation in color between bright galaxies and their faint companions in this cluster is statistically significant with a confidence level of 98.7%. The statistical significance increases if we additionally remove non-members using the Sloan Digital Sky Survey photometric redshift information (∼2.6σ and 99.3%). Our results suggest three possible scenarios: (1) vestiges of infallen groups, (2) dwarf capturing, and (3) tidal tearing of bright galaxies.

19. Inside-Out or Outside-In? Metallicity Gradients in Low Surface Brightness Galaxies in the MUSCEL Program

Young, Jason; Kuzio de Naray, Rachel; Xuesong Wang, Sharon

2016-01-01

We present the metallicity profiles of three low surface brightness (LSB) galaxies as clues to the formation of these galaxies. This easily overlooked class of galaxy comprises up to half of the galaxy population with masses spanning that of the Milky Way, making them cosmologically significant baryon repositories. LSB galaxies are also very different from the more familiar archetypal galaxies in that they have unusually high gas fractions, up to 95%. Yet, they do not represent a distinct class of galaxy, but are simply on the low surface brightness end of a continuum.We have observed a sample of low surface brightness galaxies with the VIRUS-P integral field spectrograph as part of the MUSCEL program (MUltiwavelength observations of the Structure, Chemistry, and Evolution of LSB galaxies). Our program aims to fully characterize the formation histories of these galaxies by using these data in tandem with Spitzer, Galex, and Swift observations.Optical emission lines contained within the VIRUS-P spectra have allowed us to determined the metallicities of HII regions within these galaxies via emission-line ratio diagnostics. Because ISM metallicities are directly linked to the competing effects of star formation and gas accretion, the distribution of metals is a significant clue to the formation of these galaxies.

20. SIMULTANEOUS MULTI-BAND DETECTION OF LOW SURFACE BRIGHTNESS GALAXIES WITH MARKOVIAN MODELING

Vollmer, B.; Bonnarel, F.; Louys, M. [CDS, Observatoire Astronomique, UMR 7550, 11 rue de l' universite, F-67000 Strasbourg (France); Perret, B.; Petremand, M.; Lavigne, F.; Collet, Ch. [LSIIT, Universite de Strasbourg, 7, Rue Rene Descartes, F-67084 Strasbourg (France); Van Driel, W. [GEPI, Observatoire de Paris, CNRS, Universite Paris Diderot, 5 place Jules Janssen, F-92190 Meudon (France); Sabatini, S. [INAF/IASF-Roma, via Fosso de Cavaliere 100, I-00133 Roma (Italy); MacArthur, L. A., E-mail: Bernd.Vollmer@astro.unistra.fr [Herzberg Institute of Astrophysics, National Research Council of Canada, Victoria, BC V9E 2E7 (Canada)

2013-02-01

We present to the astronomical community an algorithm for the detection of low surface brightness (LSB) galaxies in images, called MARSIAA (MARkovian Software for Image Analysis in Astronomy), which is based on multi-scale Markovian modeling. MARSIAA can be applied simultaneously to different bands. It segments an image into a user-defined number of classes, according to their surface brightness and surroundings-typically, one or two classes contain the LSB structures. We have developed an algorithm, called DetectLSB, which allows the efficient identification of LSB galaxies from among the candidate sources selected by MARSIAA. The application of the method to two and three bands simultaneously was tested on simulated images. Based on our tests, we are confident that we can detect LSB galaxies down to a central surface brightness level of only 1.5 times the standard deviation from the mean pixel value in the image background. To assess the robustness of our method, the method was applied to a set of 18 B- and I-band images (covering 1.3 deg{sup 2} in total) of the Virgo Cluster to which Sabatini et al. previously applied a matched-filter dwarf LSB galaxy search algorithm. We have detected all 20 objects from the Sabatini et al. catalog which we could classify by eye as bona fide LSB galaxies. Our method has also detected four additional Virgo Cluster LSB galaxy candidates undetected by Sabatini et al. To further assess the completeness of the results of our method, both MARSIAA, SExtractor, and DetectLSB were applied to search for (1) mock Virgo LSB galaxies inserted into a set of deep Next Generation Virgo Survey (NGVS) gri-band subimages and (2) Virgo LSB galaxies identified by eye in a full set of NGVS square degree gri images. MARSIAA/DetectLSB recovered {approx}20% more mock LSB galaxies and {approx}40% more LSB galaxies identified by eye than SExtractor/DetectLSB. With a 90% fraction of false positives from an entirely unsupervised pipeline, a completeness of

1. Detecting edges in the X-ray surface brightness of galaxy clusters

Sanders, J S; Russell, H R; Walker, S A; Blundell, K M

2016-01-01

The effects of many physical processes in the intracluster medium of galaxy clusters imprint themselves in X-ray surface brightness images. It is therefore important to choose optimal methods for extracting information from and enhancing the interpretability of such images. We describe in detail a gradient filtering edge detection method that we previously applied to images of the Centaurus cluster of galaxies. The Gaussian gradient filter measures the gradient in the surface brightness distribution on particular spatial scales. We apply this filter on different scales to Chandra X-ray observatory images of two clusters with AGN feedback, the Perseus cluster and M87, and a merging system, A3667. By combining filtered images on different scales using radial filters spectacular images of the edges in a cluster are produced. We describe how to assess the significance of features in filtered images. We find the gradient filtering technique to have significant advantages for detecting many kinds of features compar...

2. HOW TO IDENTIFY AND SEPARATE BRIGHT GALAXY CLUSTERS FROM THE LOW-FREQUENCY RADIO SKY

In this work, we simulate the 50-200 MHz radio sky that is constrained in the field of view (50 radius) of the 21 Centimeter Array (21CMA), a low-frequency radio interferometric array constructed in the remote area of Xinjiang, China, by carrying out Monte Carlo simulations to model the strong contaminating foreground of the redshifted cosmological reionization signals, including emissions from our Galaxy, galaxy clusters, and extragalactic discrete sources (i.e., star-forming galaxies, radio-quiet active galactic nuclei (AGNs), and radio-loud AGNs). As an improvement over previous works, we consider in detail not only random variations of morphological and spectroscopic parameters within the ranges allowed by multi-band observations, but also the evolution of radio halos in galaxy clusters, assuming that relativistic electrons are re-accelerated in the intracluster medium (ICM) in merger events and lose energy via both synchrotron emission and inverse Compton scattering with cosmic microwave background photons. By introducing a new approach designed on the basis of independent component analysis and wavelet detection algorithm, we prove that, with a cumulative observation of one month with the 21CMA array, about 80% of galaxy clusters (37 out of 48 clusters assuming a mean magnetic field of B = 2 μG in the ICM, or 15 out of 18 clusters assuming B = 0.2 μG) with central brightness temperatures of >10 K at 65 MHz can be safely identified and separated from the overwhelmingly bright foreground. By examining the brightness temperature images and spectra extracted from these identified clusters, we find that the morphological and spectroscopic distortions are extremely small compared to the input simulated clusters, and the reduced χ2 of brightness temperature profiles and spectra are controlled to be ∼<0.5 and ∼<1.3, respectively. These results robustly indicate that in the near future a sample of dozens of bright galaxy clusters will be disentangled from the

3. Modelling the spectro-photometric and chemical evolution of Low Surface Brightness spiral galaxies

Hoek, L. B. van den; de Blok, W J G

1995-01-01

We investigate the star formation history and chemical evolution of Low Surface Brightness (LSB) spiral galaxies by means of their observed spectro-photometric and chemical properties. We present preliminary results for Johnson-Cousins UBVRI magnitudes and stellar [O/H] abundance ratios using a galactic chemical evolution model incorporating a detailed metallicity dependent set of stellar input data covering all relevant stages of stellar evolution. Comparison of our model results with observ...

4. Multiband optical surface brightness profile decompositions of the Seyfert galaxies Mrk 79 and NGC 5548

Mihov, Boyko; Slavcheva-Mihova, Lyuba

2007-01-01

We present preliminary results of the Johnson-Cousins (U)BVRI surface brightness profile decompositions of the Seyfert galaxies Mrk 79 and NGC 5548. The profiles were modelled as a sum of a Gaussian law for the nucleus, a Sersic law for the bulge and an exponent law for the disk. A flat bar was added to the model profile of Mrk 79. The parameters and the total magnitudes of the structural components were derived.

5. A UNIFIED EMPIRICAL MODEL FOR INFRARED GALAXY COUNTS BASED ON THE OBSERVED PHYSICAL EVOLUTION OF DISTANT GALAXIES

Bethermin, Matthieu; Daddi, Emanuele; Sargent, Mark T.; Elbaz, David; Mullaney, James; Pannella, Maurilio [Laboratoire AIM-Paris-Saclay, CEA/DSM/Irfu - CNRS - Universite Paris Diderot, CEA-Saclay, Orme des Merisiers, F-91191 Gif-sur-Yvette (France); Magdis, Georgios [Department of Physics, University of Oxford, Keble Road, Oxford, OX1 3RH (United Kingdom); Hezaveh, Yashar [Department of Physics, McGill University, 3600 Rue University, Montreal, Quebec H3A 2T8 (Canada); Le Borgne, Damien [UPMC Univ. Paris 06, UMR7095, Institut d' Astrophysique de Paris, F-75014 Paris (France); Buat, Veronique [Laboratoire d' Astrophysique de Marseille, OAMP, Universite Aix-Marseille, CNRS, 38 rue Frederic Joliot-Curie, F-13388 Marseille Cedex 13 (France); Charmandaris, Vassilis [Department of Physics and Institute of Theoretical and Computation Physics, University of Crete, 71003 Heraklion (Greece); Lagache, Guilaine [Institut d' Astrophysique Spatiale (IAS), batiment 121, Universite Paris-Sud 11 and CNRS (UMR 8617), F-91405 Orsay (France); Scott, Douglas, E-mail: matthieu.bethermin@cea.fr [Department of Physics and Astronomy, University of British Columbia, 6224 Agricultural Road, Vancouver, BC V6T 1Z1 (Canada)

2012-10-01

We reproduce the mid-infrared to radio galaxy counts with a new empirical model based on our current understanding of the evolution of main-sequence (MS) and starburst (SB) galaxies. We rely on a simple spectral energy distribution (SED) library based on Herschel observations: a single SED for the MS and another one for SB, getting warmer with redshift. Our model is able to reproduce recent measurements of galaxy counts performed with Herschel, including counts per redshift slice. This agreement demonstrates the power of our 2-Star-Formation Modes (2SFM) decomposition in describing the statistical properties of infrared sources and their evolution with cosmic time. We discuss the relative contribution of MS and SB galaxies to the number counts at various wavelengths and flux densities. We also show that MS galaxies are responsible for a bump in the 1.4 GHz radio counts around 50 {mu}Jy. Material of the model (predictions, SED library, mock catalogs, etc.) is available online.

6. The Bright End of the Luminosity Function of Red Sequence Galaxies

Loh, Y S; Loh, Yeong-Shang; Strauss, Michael A.

2006-01-01

We study the bright end of the luminosity distribution of galaxies in fields with Luminous Red Galaxies (LRG) from the Sloan Digital Sky Survey (SDSS). Using 2099 square degree of SDSS imaging data, we search for luminous (> L*) early-type galaxies within 1.0 Mpc/h of a volume-limited sample of 12,608 spectroscopic LRG in the redshift range 0.12 < z < 0.38. Most of these objects lie in rich environments, with the LRG being the brightest object within 1.0 Mpc/h. The luminosity gap, M12, between the first and second-rank galaxies within 1.0 Mpc/h is large (~0.8 mag), substantially larger than can be explained with an exponentially decaying luminosity function of galaxies. The brightest member is less luminous (by 0.1 to 0.2 mag), and shows a larger gap in LRG selected groups than in cluster-like environments. The large luminosity gap shows little evolution with redshift to z = 0.4, ruling out the scenario that these LRG selected brightest cluster or group galaxies grow by recent cannibalism of cluster mem...

7. Dust Temperatures in the Infrared Space Observatory Atlas of Bright Spiral Galaxies

Bendo, G J; Wells, M; Gallais, P; Haas, M; Heras, A M; Klaas, U; Laureijs, R J; Leech, K; Lemke, D; Metcalfe, L; Rowan-Robinson, M; Schulz, B; Telesco, C M; Bendo, George J.; Joseph, Robert D.; Wells, Martyn; Gallais, Pascal; Haas, Martin; Heras, Ana M.; Klaas, Ulrich; Laureijs, Rene J.; Leech, Kieron; Lemke, Dietrich; Metcalfe, Leo; Rowan-Robinson, Michael; Schulz, Bernhard; Telesco, Charles

2003-01-01

We examine far-infrared and submillimeter spectral energy distributions for galaxies in the Infrared Space Observatory Atlas of Bright Spiral Galaxies. For the 71 galaxies where we had complete 60-180 micron data, we fit blackbodies with lambda^-1 emissivities and average temperatures of 31 K or lambda^-2 emissivities and average temperatures of 22 K. Except for high temperatures determined in some early-type galaxies, the temperatures show no dependence on any galaxy characteristic. For the 60-850 micron range in eight galaxies, we fit blackbodies with lambda^-1, lambda-2, and lambda^-beta (with beta variable) emissivities to the data. The best results were with the lambda^-beta emissivities, where the temperatures were ~30 K and the emissivity coefficient beta ranged from 0.9 to 1.9. These results produced gas to dust ratios that ranged from 150 to 580, which were consistent with the ratio for the Milky Way and which exhibited relatively little dispersion compared to fits with fixed emissivities.

8. The Role of Clustering of Sub-Clumps in Bright Elliptical Galaxy Formation from a Low-Spin Seed Galaxy

Kawata, D

2001-01-01

We reveal the role of clustering of sub-clumps, which is expected in the cold dark matter (CDM) universe, in forming a bright elliptical galaxy (BEG) from a low-spin seed galaxy. This can be done by comparing the evolution of a low-spin seed galaxy including small-scale density fluctuations expected in the CDM universe (Model 1) with that of a completely uniform one (Model 2), using numerical experiments. We show that Model 2 cannot reproduce the properties of BEGs and forms a disk which is too compact and too bright due to the conservation of the initial-small angular momentum. In Model 1 clustering of the sub-clumps caused by initial small-scale density fluctuations leads to angular momentum transfer from the baryon component to the dark matter and consequently a nearly spherical system supported by random motions is formed. Moreover the collisionless property of the stars formed in the sub-clumps prevents the dissipative contraction of the system, leading to a large measured half-light radius. As a result,...

9. Source Plane Reconstruction of the Bright Lensed Galaxy RCSGA 032727-132609

Sharon, Keren; Gladders, Michael D.; Rigby, Jane R.; Wuyts, Eva; Koester, Benjamin P.; Bayliss, Matthew B.; Barrientos, L. Felipe

2011-01-01

We present new HST/WFC3 imaging data of RCS2 032727-132609, a bright lensed galaxy at z=1.7 that is magnified and stretched by the lensing cluster RCS2 032727-132623. Using this new high-resolution imaging, we modify our previous lens model (which was based on ground-based data) to fully understand the lensing geometry, and use it to reconstruct the lensed galaxy in the source plane. This giant arc represents a unique opportunity to peer into 100-pc scale structures in a high redshift galaxy. This new source reconstruction will be crucial for a future analysis of the spatially-resolved rest-UV and rest-optical spectra of the brightest parts of the arc.

10. B and R CCD surface photometry of selected low surface brightness galaxies in the region of the Fornax cluster

The recent discoveries of large numbers of low surface brightness (LSB) galaxies in clusters and of the extreme LSB giant galaxy Malin 1 are changing our view of the galactic contents of the Universe. In this paper we describe B and R band CCD photometry of a sample of LSB galaxies previously identified from photographic plates of the Fornax cluster. This sample contains some of the lowest surface brightness galaxies known, one having the same central surface brightness as Main 1. The objects in this sample have a wide range of morphologies, and galaxies of similar appearance may have very different (B-R) colours. The range of (B-R) colours for this sample (almost all of which would have been described as dE from their B band morphology alone) is as large as that of the entire Hubble sequence. (author)

11. HerMES: A Deficit in the Surface Brightness of the Cosmic Infrared Background due to Galaxy Cluster Gravitational Lensing

Zemcov, M.; Blain, A.; Cooray, A.; Béthermin, M.; Bock, J.; Clements, D. L.; Conley, A.; Conversi, L.; Dowell, C. D.; Farrah, D.; Glenn, J.; Griffin, M.; Halpern, M.; Jullo, E.; Kneib, J.-P.; Marsden, G.; Nguyen, H. T.; Oliver, S. J.; Richard, J.; Roseboom, I. G.; Schulz, B.; Scott, Douglas; Shupe, D. L.; Smith, A. J.; Valtchanov, I.; Viero, M.; Wang, L.; Wardlow, J.

2013-06-01

We have observed four massive galaxy clusters with the SPIRE instrument on the Herschel Space Observatory and measure a deficit of surface brightness within their central region after removing detected sources. We simulate the effects of instrumental sensitivity and resolution, the source population, and the lensing effect of the clusters to estimate the shape and amplitude of the deficit. The amplitude of the central deficit is a strong function of the surface density and flux distribution of the background sources. We find that for the current best fitting faint end number counts, and excellent lensing models, the most likely amplitude of the central deficit is the full intensity of the cosmic infrared background (CIB). Our measurement leads to a lower limit to the integrated total intensity of the CIB of I_{250 \\, \\mu {m}} \\gt 0.69_{-0.03}^{+0.03} ({stat.}) _{-0.06}^{+0.11} ({sys.}) MJy sr-1, with more CIB possible from both low-redshift sources and from sources within the target clusters. It should be possible to observe this effect in existing high angular resolution data at other wavelengths where the CIB is bright, which would allow tests of models of the faint source component of the CIB. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.

12. HerMES: A DEFICIT IN THE SURFACE BRIGHTNESS OF THE COSMIC INFRARED BACKGROUND DUE TO GALAXY CLUSTER GRAVITATIONAL LENSING

Zemcov, M.; Cooray, A.; Bock, J.; Dowell, C. D.; Nguyen, H. T. [California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125 (United States); Blain, A. [Physics and Astronomy, University of Leicester, University Road, Leicester LE1 7RH (United Kingdom); Bethermin, M. [Laboratoire AIM-Paris-Saclay, CEA/DSM/Irfu-CNRS-Universite Paris Diderot, CE-Saclay, pt courrier 131, F-91191 Gif-sur-Yvette (France); Clements, D. L. [Astrophysics Group, Imperial College London, Blackett Laboratory, Prince Consort Road, London SW7 2AZ (United Kingdom); Conley, A.; Glenn, J. [Center for Astrophysics and Space Astronomy 389-UCB, University of Colorado, Boulder, CO 80309 (United States); Conversi, L. [Herschel Science Centre, European Space Astronomy Centre, Villanueva de la Canada, E-28691 Madrid (Spain); Farrah, D.; Oliver, S. J.; Roseboom, I. G. [Astronomy Centre, Department of Physics and Astronomy, University of Sussex, Brighton BN1 9QH (United Kingdom); Griffin, M. [School of Physics and Astronomy, Cardiff University, Queens Buildings, The Parade, Cardiff CF24 3AA (United Kingdom); Halpern, M.; Marsden, G. [Department of Physics and Astronomy, University of British Columbia, 6224 Agricultural Road, Vancouver, BC V6T 1Z1 (Canada); Jullo, E.; Kneib, J.-P. [Aix-Marseille Universite, CNRS, LAM (Laboratoire d' Astrophysique de Marseille) UMR7326, F-13388 Marseille (France); Richard, J., E-mail: zemcov@caltech.edu [Centre de Recherche Astronomique de Lyon, Universite Lyon 1, 9 avenue Charles Andre, F-69230 Saint-Genis Laval (France); and others

2013-06-01

We have observed four massive galaxy clusters with the SPIRE instrument on the Herschel Space Observatory and measure a deficit of surface brightness within their central region after removing detected sources. We simulate the effects of instrumental sensitivity and resolution, the source population, and the lensing effect of the clusters to estimate the shape and amplitude of the deficit. The amplitude of the central deficit is a strong function of the surface density and flux distribution of the background sources. We find that for the current best fitting faint end number counts, and excellent lensing models, the most likely amplitude of the central deficit is the full intensity of the cosmic infrared background (CIB). Our measurement leads to a lower limit to the integrated total intensity of the CIB of I{sub 250{mu}m}>0.69{sub -0.03}{sup +0.03}(stat.){sub -0.06}{sup +0.11}(sys.) MJy sr{sup -1}, with more CIB possible from both low-redshift sources and from sources within the target clusters. It should be possible to observe this effect in existing high angular resolution data at other wavelengths where the CIB is bright, which would allow tests of models of the faint source component of the CIB.

13. Galaxy cluster number count data constraints on cosmological parameters

Campanelli, L. [Universita di Bari, Dipartimento di Fisica, Bari (Italy); Fogli, G.L.; Marrone, A. [Universita di Bari, Dipartimento di Fisica, Bari (Italy); INFN-Sezione di Bari, Bari (Italy); Kahniashvili, T. [Carnegie Mellon University, McWilliams Center for Cosmology and Department of Physics, Pittsburgh, PA (United States); Laurentian University, Department of Physics, Sudbury, ON (Canada); Ilia State University, Abastumani Astrophysical Observatory, Tbilisi (Georgia); Ratra, Bharat [Kansas State University, Department of Physics, Manhattan, KS (United States)

2012-11-15

We use data on massive galaxy clusters (M{sub cluster}>8 x 10{sup 14} h{sup -1} M{sub s}un within a comoving radius of R{sub cluster}=1.5h{sup -1} Mpc) in the redshift range 0.05count derived from the observational temperature data. We show that, contrary to previous analyses, cluster data alone prefer low values of the amplitude of mass fluctuations, {sigma}{sub 8}{<=}0.69 (1 {sigma} C.L.), and large amounts of nonrelativistic matter, {Omega}{sub m} {>=}0.38 (1 {sigma} C.L.), in slight tension with the {Lambda}CDM concordance cosmological model, though the results are compatible with {Lambda}CDM at 2 {sigma}. In addition, we derive a {sigma}{sub 8} normalization relation, {sigma}{sub 8}{Omega}{sub m}{sup 1/3} = 0.49 {+-} 0.06 (2{sigma} C.L.). Combining cluster data with {sigma}{sub 8}-independent baryon acoustic oscillation observations, cosmic microwave background data, Hubble constant measurements, Hubble parameter determination from passively evolving red galaxies, and magnitude-redshift data of type Ia supernovae, we find {Omega}{sub m} = 0.28{sup +0.03}{sub -0.02} and {sigma}{sub 8} = 0.73{sup +0.03}{sub -0.03}, the former in agreement and the latter being slightly lower than the corresponding values in the concordance cosmological model. We also find H{sub 0} = 69.1{sup +1

14. Luminosity and surface brightness distribution of K-band galaxies from the UKIDSS Large Area Survey

Smith, Anthony J; Cross, Nicholas J G

2008-01-01

We present luminosity and surface brightness distributions of 36,663 galaxies with K-band photometry from the UKIRT Infrared Deep Sky Survey (UKIDSS) Large Area Survey (LAS), Data Release 3 and optical photometry from Data Release 5 of the Sloan Digital Sky Survey (SDSS). Various features and limitations of the new UKIDSS data are examined, such as a problem affecting Petrosian magnitudes of extended sources. Selection limits in K- and r-band magnitude, K-band surface brightness and K-band radius are included explicitly in the 1/Vmax estimation of the space density and luminosity function. The bivariate brightness distribution in K-band absolute magnitude and surface brightness is presented and found to display a clear luminosity-surface brightness correlation that flattens at high luminosity and broadens at low luminosity, consistent with similar analyses at optical wavelengths. Best fitting Schechter function parameters for the K-band luminosity function are found to be M*-5log h=-23.17 +/- 0.04, alpha=-0.8...

15. Hubble Space Telescope Imaging of Globular Cluster Candidates in Low Surface Brightness Dwarf Galaxies

Sharina, M E; Makarov, D I; Sharina, Margarita E.; Puzia, Thomas H.; Makarov, Dmitry I.

2005-01-01

Fifty-seven nearby low surface brightness dwarf galaxies were searched for globular cluster candidates (GCCs) using Hubble Space Telescope WFPC2 imaging in V and I. The sample consists of 18 dwarf spheroidal (dSph), 36 irregular (dIrr), and 3 "transition" type (dIrr/dSph) galaxies with angular sizes less than 3.7 kpc situated at distances 2-6 Mpc in the field and in the nearby groups: M81, Centaurus A, Sculptor, Canes Venatici I cloud. We find that ~50% of dSph, dIrr/dSph, and dIrr galaxies contain GCCs. The fraction of GCCs located near the center of dwarf spheroidal galaxies is >2 times higher than that for dIrrs. The mean integral color of GCCs in dSphs, V-I = 1.04+/-0.16 mag, coincides with the corresponding value for Galactic globular clusters and is similar to the blue globular cluster sub-populations in massive early-type galaxies. The color distribution for GCCs in dIrrs shows a clear bimodality with peaks near V-I = 0.5 and 1.0 mag. Blue GCCs are presumably young with ages t -6.5 mag in both dSph an...

16. Initial Results from the Nobeyama Molecular Gas Observations of Distant Bright Galaxies

Iono, D; Kohno, K; Kawabe, R; Ikarashi, S; Ichikawa, K; Kodama, T; Motohara, K; Nakajima, T; Nakanishi, K; Ohta, K; Ota, K; Saito, T; Suzuki, K; Tadaki, K; Tamura, Y; Ueda, J; Umehata, H; Yabe, K; Yoshida, T; Yuma, S; Kuno, N; Takano, S; Iwashita, H; Handa, K; Higuchi, A; Hirota, A; Ishikawa, S; Kimura, K; Maekawa, J; Mikoshiba, H; Miyazawa, C; Miyazawa, K; Muraoka, K; Ogawa, H; Onodera, S; Saito, Y; Sakai, T; Takahashi, S; Yun, M S

2012-01-01

We present initial results from the CO survey toward high redshift galaxies using the Nobeyama 45m telescope. Using the new wide bandwidth spectrometer equipped with a two-beam SIS receiver, we have robust new detections of three high redshift (z=1.6-3.4) submillimeter galaxies (SXDF 1100.001, SDP9, and SDP17), one tentative detection (SDSS J160705+533558), and one non-detection (COSMOS-AzTEC1). The galaxies observed during the commissioning phase are sources with known spectroscopic redshifts from previous optical or from wide-band submm spectroscopy. The derived molecular gas mass and line widths from Gaussian fits are ~10^11 Msun and 430-530 km/s, which are consistent with previous CO observations of distant submm galaxies and quasars. The spectrometer that allows a maximum of 32 GHz instantaneous bandwidth will provide new science capabilities at the Nobeyama 45m telescope, allowing us to determine redshifts of bright submm selected galaxies without any prior redshift information.

17. A New Constraint on the Ly$\\alpha$ Fraction of UV Very Bright Galaxies at Redshift 7

Furusawa, Hisanori; Kobayashi, Masakazu A R; Dunlop, James S; Shimasaku, Kazuhiro; Takata, Tadafumi; Sekiguchi, Kazuhiro; Naito, Yoshiaki; Furusawa, Junko; Ouchi, Masami; Nakata, Fumiaki; Yasuda, Naoki; Okura, Yuki; Taniguchi, Yoshiaki; Yamada, Toru; Kajisawa, Masaru; Fynbo, Johan P U; Fevre, Olivier Le

2016-01-01

We study the extent to which very bright (-23.0 50 Angstrom, which we estimate to be < 0.23. This result may indicate a weak trend where the fraction of strong Lya emitters ceases to rise, and possibly falls between z~6 and z~7. Our results also leave open the possibility that strong Lya may still be more prevalent in the brightest galaxies in the reionization era than their fainter counterparts. A larger spectroscopic sample of galaxies is required to derive a more reliable constraint on the neutral hydrogen fraction at z~7 based on the Lya fraction in the bright galaxies.

18. Simulating a slow bar in the low surface brightness galaxy UGC 628

Chequers, Matthew H; Widrow, Lawrence M; Gilhuly, Colleen

2016-01-01

We present a disc-halo N-body model of the low surface brightness galaxy UGC 628, one of the few systems that harbours a "slow" bar with a ratio of corotation radius to bar length of $\\mathcal{R} \\equiv R_c/a_b \\sim 2$. We select our initial conditions using SDSS DR10 photometry, a physically motivated radially variable mass-to-light ratio profile, and rotation curve data from the literature. A global bar instability grows in our submaximal disc model, and the disc morphology and dynamics agree broadly with the photometry and kinematics of UGC 628 at times between peak bar strength and the onset of buckling. Prior to bar formation, the disc and halo contribute roughly equally to the potential in the galaxy's inner region, giving the disc enough self gravity for bar modes to grow. After bar formation there is significant mass redistribution, creating a baryon dominated inner and dark matter dominated outer disc. This implies that, unlike most other low surface brightness galaxies, UGC 628 is not dark matter do...

19. Simultaneous multi-band detection of Low Surface Brightness galaxies with Markovian modelling

Vollmer, B; Petremand, M; Lavigne, F; Collet, Ch; van Driel, W; Bonnarel, F; Louys, M; Sabatini, S; MacArthur, L A

2012-01-01

We present an algorithm for the detection of Low Surface Brightness (LSB) galaxies in images, called MARSIAA (MARkovian Software for Image Analysis in Astronomy), which is based on multi-scale Markovian modeling. MARSIAA can be applied simultaneously to different bands. It segments an image into a user-defined number of classes, according to their surface brightness and surroundings - typically, one or two classes contain the LSB structures. We have developed an algorithm, called DetectLSB, which allows the efficient identification of LSB galaxies from among the candidate sources selected by MARSIAA. To assess the robustness of our method, the method was applied to a set of 18 B and I band images (covering 1.3 square degrees in total) of the Virgo cluster. To further assess the completeness of the results of our method, both MARSIAA, SExtractor, and DetectLSB were applied to search for (i) mock Virgo LSB galaxies inserted into a set of deep Next Generation Virgo Survey (NGVS) gri-band subimages and (ii) Virgo...

20. The complex evolutionary paths of local infrared bright galaxies: a high angular resolution mid-infrared view

Alonso-Herrero, A; Roche, P F; Hernan-Caballero, A; Aretxaga, I; Martinez-Paredes, M; Almeida, C Ramos; Pereira-Santaella, M; Diaz-Santos, T; Levenson, N A; Packham, C; Colina, L; Esquej, P; Gonzalez-Martin, O; Ichikawa, K; Imanishi, M; Espinosa, J M Rodriguez; Telesco, C

2016-01-01

We investigate the evolutionary connection between local IR-bright galaxies ($\\log L_{\\rm IR}\\ge 11.4\\,L_\\odot$) and quasars. We use high angular resolution ($\\sim$ 0.3-0.4 arcsec $\\sim$ few hundred parsecs) $8-13\\,\\mu$m ground-based spectroscopy to disentangle the AGN mid-IR properties from those of star formation. The comparison between the nuclear $11.3\\,\\mu$m PAH feature emission and that measured with Spitzer/IRS indicates that the star formation is extended over a few kpc in the IR-bright galaxies. The AGN contribution to the total IR luminosity of IR-bright galaxies is lower than in quasars. Although the dust distribution is predicted to change as IR-bright galaxies evolve to IR-bright quasars and then to optical quasars, we show that the AGN mid-IR emission of all the quasars in our sample is not significantly different. In contrast, the nuclear emission of IR-bright galaxies with low AGN contributions appears more heavily embedded in dust although there is no clear trend with the interaction stage or...

1. Bright z ~ 3 Lyman break galaxies in deep wide field surveys

Bian, Fuyan

In my thesis I investigate the luminous z ˜ 3 Lyman break galaxies in deep wide field surveys. In the first part of the thesis, I use the LBT/LUCIFER to observe a lensed high-redshift star-forming galaxy (J0900+2234) at z = 2.03. With the high S/N near-IR spectroscopic observations, I reveal the detailed physical properties of this high-redshift galaxy, including SFR, metallicity, dust extinction, dynamical mass, and electron number density. In the second part of the thesis, I select a large sample of LBGs at z ˜ 3 from our new LBT Bootes field survey, and study the bright end luminosity function (LF), stellar mass function (SMF) and clustering properties of bright LBGs (1L* < L < 2.5L*). Together with other LF and SMF measurements, the evolution of LF and SMF can be well described by continuously rising star formation history model. Using the clustering measurements in this work and other works, a tight relation between the average host galaxy halo mass and the galaxy star formation rate is found, which can be interpreted as arising from cold flow accretion. The relation also suggests that the cosmic star formation efficiency is about 5%-20% of the total cold flow mass. This cosmic star formation efficiency does not evolve with redshift (from z ˜ 5 to z ˜ 3), hosting dark matter halo mass (1011 -- 1013 M⊙ ), or galaxy luminosity (from 0.3L* to 3L* ). In the third and fourth parts, with the spectroscopic follow-up observations of the bright LBGs, I establish a sample of spectroscopically-confirmed ultraluminous LBGs (ULBGs) in NOAO Boo¨tes field. With this new ULBG sample, the rest-frame UV LF of LBG at M1700A = -23.0 was measured for the first time. I find that the ULBGs have larger outflow velocity, broader Lyalpha emission and ISM absorption line profiles, and more prominent C IV P-Cygni profile. This profile may imply a top-heavy IMF in these ULBGs. The ULBGs have larger stellar mass and SFR, but smaller dust extinction than the typical L* LBGs at z ˜ 2

2. UV surface brightness of galaxies from the local Universe to z ~ 5

Lerner, Eric J; Scarpa, Riccardo

2014-01-01

The Tolman test for surface brightness dimming was originally proposed as a test for the expansion of the Universe. The test, which is independent of the details of the assumed cosmology,is based on comparisons of the surface brightness (SB) of identical objects at different cosmological distances. Claims have been made that the Tolman test provides compelling evidence against a static model for the Universe. In this paper we reconsider this subject by adopting a static Euclidean Universe with a linear Hubble relation at all z (which is not the standard Einstein- de Sitter model),resulting in a relation between flux and luminosity that is virtually indistinguishable from the one used for LCDM models. Based on the analysis of the UV surface brightness of luminous disk galaxies from HUDF and GALEX datasets, reaching from the local Universe to z ~ 5 we show that the surface brightness remains constant as expected in a SEU. A re-analysis of previously-published data used for the Tolman test at lower redshift, whe...

3. Galaxy number counts to second order and their bispectrum

Di Dio, Enea; Marozzi, Giovanni; Montanari, Francesco

2014-01-01

We determine the number counts to second order in cosmological perturbation theory in the Poisson gauge and allowing for anisotropic stress. The calculation is performed using an innovative approach based on the recently proposed "geodesic light-cone" gauge. This allows us to determine the number counts in a purely geometric way, without using Einstein's equation. The result is valid for general dark energy models and (most) modified gravity models. We then evaluate numerically the relevant contributions to the number counts bispectrum. In particular we consider the terms involving the density, redshift space distortion and lensing.

4. Galaxy number counts to second order and their bispectrum

Dio, Enea Di; Durrer, Ruth; Marozzi, Giovanni; Montanari, Francesco, E-mail: Enea.DiDio@unige.ch, E-mail: Ruth.Durrer@unige.ch, E-mail: Giovanni.Marozzi@unige.ch, E-mail: Francesco.Montanari@unige.ch [Université de Genève, Département de Physique Théorique and CAP, 24 quai Ernest-Ansermet, CH-1211 Genève 4 (Switzerland)

2014-12-01

We determine the number counts to second order in cosmological perturbation theory in the Poisson gauge and allowing for anisotropic stress. The calculation is performed using an innovative approach based on the recently proposed ''geodesic light-cone'' gauge. This allows us to determine the number counts in a purely geometric way, without using Einstein's equation. The result is valid for general dark energy models and (most) modified gravity models. We then evaluate numerically some relevant contributions to the number counts bispectrum. In particular we consider the terms involving the density, redshift space distortion and lensing.

5. AEGIS: The Diversity of Bright Near-IR Selected Distant Red Galaxies

Conselice, C J; Georgakakis, A; Almaini, O; Coil, A L; Cooper, M C; Eisenhardt, P; Foucaud, S; Koekemoer, A; Lotz, J; Noeske, K F; Weiner, B; Willmer, C N A

2006-01-01

We use deep and wide near infrared (NIR) imaging from the Palomar telescope combined with DEEP2 spectroscopy and Hubble Space Telescope (HST) and Chandra Space Telescope imaging to investigate the nature of galaxies that are red in NIR colors. We locate these distant red galaxies' (DRGs) through the color cut (J-K)_{vega} > 2.3 over 0.7 deg^{2}, where we find 1010 DRG candidates down to K_s = 20.5. We combine 95 high quality spectroscopic redshifts with photometric redshifts from BRIJK photometry to determine the redshift and stellar mass distributions for these systems, and morphological/structural and X-ray properties for 107 DRGs in the Extended Groth Strip. We find that many bright (J-K)_{vega}>2.3 galaxies with K_s2 systems massive with M_*>10^{11} M_solar. HST imaging shows that the structural properties and morphologies of DRGs are also diverse, with the majority elliptical/compact (57%), and the remainder edge-on spirals (7%), and peculiar galaxies (29%). The DRGs at z < 1.4 with high quality spec...

6. Higher order relativistic galaxy number counts: dominating terms

Nielsen, Jeppe Trøst

2016-01-01

We review the number counts to second order concentrating on the terms which dominate on sub horizon scales. We re-derive the result for these terms and compare it with the different versions found in the literature. We generalize our derivation to higher order terms, especially the third order number counts which are needed to compute the 1-loop contribution to the power spectrum.

7. Detecting edges in the X-ray surface brightness of galaxy clusters

Sanders, J. S.; Fabian, A. C.; Russell, H. R.; Walker, S. A.; Blundell, K. M.

2016-08-01

The effects of many physical processes in the intracluster medium of galaxy clusters imprint themselves in X-ray surface brightness images. It is therefore important to choose optimal methods for extracting information from and enhancing the interpretability of such images. We describe in detail a gradient filtering edge detection method that we previously applied to images of the Centaurus cluster of galaxies. The Gaussian gradient filter measures the gradient in the surface brightness distribution on particular spatial scales. We apply this filter on different scales to Chandra X-ray observatory images of two clusters with active galactic nucleus feedback, the Perseus cluster and M 87, and a merging system, A 3667. By combining filtered images on different scales using radial filters spectacular images of the edges in a cluster are produced. We describe how to assess the significance of features in filtered images. We find the gradient filtering technique to have significant advantages for detecting many kinds of features compared to other analysis techniques, such as unsharp masking. Filtering cluster images in this way in a hard energy band allows shocks to be detected.

8. Multiwavelength study of nearly face-on low surface brightness disk galaxies

Gao, Dong; Liu, Shun-Fang; Zhong, Guo-Hu; Chen, Xiao-Yan; Yang, Yan-Bin; Hammer, Francois; Yang, Guo-Chao; Deng, Li-Cai; Hu, Jing-Yao

2010-01-01

We study the ages of a large sample (1,802) of nearly face-on disk low surface brightness galaxies (LSBGs) by using the evolutionary population synthesis (EPS) model PEGASE with exponential decreasing star formation rate to fit their multiwavelength spectral energy distributions (SEDs) from far-ultraviolet (FUV) to near-infrared (NIR). The derived ages of LSBGs are 1-5 Gyr for most of the sample no matter the constant or varying dust extinction is adopted, which are similar to most of the previous studies on smaller samples. This means that these LSBGs formed their majority of stars quite recently. However, a small part of the sample (~2-3%) have larger ages as 5-8 Gyr, meaning their major star forming process may occur earlier. At the same time, a large sample (5,886) of high surface brightness galaxies (HSBGs) are selected and studied in the same method for comparisons. The derived ages are 1-5 Gyr for most of the sample (97%) as well. These may mean that probably these LSBGs have no much different star for...

9. Measurable Relationship Between Bright Galaxies and Their Faint Companions in WHL J085910.0+294957, a Galaxy Cluster at z = 0.30: Vestiges of Infallen Groups?

Lee, Joon Hyeop; Kim, Minjin; Seon, Kwang-Il; Kim, Sang Chul; Yang, Soung-Chul; Ree, Chang Hee; Lee, Jong Chul; Jeong, Hyunjin; Ko, Jongwan; Choi, Changsu

2014-01-01

The properties of satellite galaxies are closely related to their host galaxies in galaxy groups. In cluster environments, on the other hand, the interaction between close neighbors is known to be limited. Our goal is to examine the relationships between host and satellite galaxies in the harsh environment of a galaxy cluster. To achieve this goal, we study a galaxy cluster WHL J085910.0+294957 at z = 0.30 using deep images obtained with CQUEAN CCD camera mounted on the 2.1-m Otto Struve telescope. After member selection based on the scaling relations of photometric and structural parameters, we investigate the relationship between bright (M_i < -18) galaxies and their faint (-18 < M_i < -15) companions. The weighted mean color of faint companion galaxies shows no significant dependence (< 1 sigma to Bootstrap uncertainties) on cluster-centric distance and local luminosity density as well as the luminosity and concentration of an adjacent bright galaxy. However, the weighted mean color shows margi...

10. Quasar-Galaxy Clustering through Projected Galaxy Counts at z=0.6-1.2

Zhang, Shao-hua; Wang, Ting-Gui; Wang, Hui-Yuan; Zhou, Hongyan

2013-01-01

We investigate the spatial clustering of galaxies around quasars at redshifts from 0.6 to 1.2 using the photometric data from Sloan Digital Sky Survey (SDSS) Stripe 82. The quasar and galaxy cross-correlation functions are measured through the projected galaxy number density n(r_p) on scales $0.05 11. QUASAR-GALAXY CLUSTERING THROUGH PROJECTED GALAXY COUNTS AT z = 0.6-1.2 We investigate the spatial clustering of galaxies around quasars at z = 0.6-1.2 using photometric data from Sloan Digital Sky Survey Stripe 82. The quasar and galaxy cross-correlation functions are measured through the projected galaxy number density n(rp ) on scales of 0.05 p –1 Mpc around quasars for a sample of 2300 quasars from Schneider et al. We detect strong clustering signals at all redshifts and find that the clustering amplitude increases significantly with redshift. We examine the dependence of quasar-galaxy clustering on quasar and galaxy properties and find that the clustering amplitude is significantly larger for quasars with more massive black holes or with bluer colors, while there is no dependence on quasar luminosity. We also show that quasars have a stronger correlation amplitude with blue galaxies than with red galaxies. We finally discuss the implications of our findings 12. The portrait of Malin 2: a case study of a giant low surface brightness galaxy Kasparova, A; Katkov, I; Chilingarian, I; Bizyaev, D 2013-01-01 The low surface brightness disc galaxy Malin2 challenges the standard theory of galaxy evolution by its enormous total mass ~2 10^12 Ms which must have been formed without recent major merger events. The aim of our work is to create a coherent picture of this exotic object by using the new optical multicolor photometric and spectroscopic observations at Apache Point Observatory as well as archival datasets from Gemini and wide-field surveys. We performed the Malin2 mass modelling, estimated the contribution of the host dark halo and found that it had acquired its low central density and the huge isothermal sphere core radius before the disc subsystem was formed. Our spectroscopic data analysis reveals complex kinematics of stars and gas in the very inner region. We measured the oxygen abundance in several clumps and concluded that the gas metallicity decreases from the solar value in the centre to a half of that at 20-30 kpc. We found a small satellite and measured its mass (1/500 of the host galaxy) and gas ... 13. HerMES: A Deficit in the Surface Brightness of the Cosmic Infrared Background Due to Galaxy Cluster Gravitational Lensing Zemcov, M; Cooray, A; Bethermin, M; Bock, J; Clements, D L; Conley, A; Conversi, L; Dowell, C D; Farrah, D; Glenn, J; Griffin, M; Halpern, M; Jullo, E; Kneib, J -P; Marsden, G; Nguyen, H T; Richard, S J Oliver J; Roseboom, I G; Schulz, B; Scott, Douglas; Shupe, D L; Smith, A J; Valtchanov, I; Viero, M; Wang, L; Wardlow, J 2013-01-01 We have observed four massive galaxy clusters with the SPIRE instrument on the Herschel Space Observatory and measure a deficit of surface brightness within their central region after subtracting sources. We simulate the effects of instrumental sensitivity and resolution, the source population, and the lensing effect of the clusters to estimate the shape and amplitude of the deficit. The amplitude of the central deficit is a strong function of the surface density and flux distribution of the background sources. We find that for the current best fitting faint end number counts, and excellent lensing models, the most likely amplitude of the central deficit is the full intensity of the cosmic infrared background (CIB). Our measurement leads to a lower limit to the integrated total intensity of the CIB of I(250 microns) > 0.69_(-0.03)^(+0.03) (stat.)_(-0.06)^(+0.11) (sys.) MJy/sr, with more CIB possible from both low-redshift sources and from sources within the target clusters. It should be possible to observe th... 14. A Bridge from Optical to Infrared Galaxies Explaining Local Properties, Predicting Galaxy Counts and the Cosmic Background Radiation Totani, T; Totani, Tomonori; Takeuchi, Tsutomu T. 2002-01-01 We give an explanation for the origin of various properties observed in local infrared galaxies, and make predictions for galaxy counts and cosmic background radiation (CBR), by a new model extended from that for optical/near-infrared galaxies. Important new characteristics of this study are that (1) mass scale dependence of dust extinction is introduced based on the size-luminosity relation of optical galaxies, and that (2) the big grain dust temperature T_dust is calculated based on a physical consideration for energy balance, rather than using the empirical relation between T_dust and total infrared luminosity L_IR found in local galaxies, which has been employed in most of previous works. Consequently, the local properties of infrared galaxies, i.e., optical/infrared luminosity ratios, L_IR-T_dust correlation, and infrared luminosity function are outputs predicted by the model. Our model indeed reproduces these local properties reasonably well. We then found considerably different results for MIR-submm co... 15. AEGIS: The Diversity of Bright Near-IR Selected Distant Red Galaxies We use deep and wide near infrared (NIR) imaging from the Palomar telescope combined with DEEP2 spectroscopy and Hubble Space Telescope (HST) and Chandra Space Telescope imaging to investigate the nature of galaxies that are red in NIR colors. We locate these 'distant red galaxies' (DRGs) through the color cut (J - K)vega > 2.3 over 0.7 deg2, where we find 1010 DRG candidates down to Ks = 20.5. We combine 95 high quality spectroscopic redshifts with photometric redshifts from BRIJK photometry to determine the redshift and stellar mass distributions for these systems, and morphological/structural and X-ray properties for 107 DRGs in the Extended Groth Strip. We find that many bright (J - K)vega > 2.3 galaxies with Ks 9 - 1012 M· , but with most z > 2 systems massive with M* > 1011 M·. HST imaging shows that the structural properties and morphologies of DRGs are also diverse, with the majority elliptical/compact (57%), and the remainder edge-on spirals (7%), and peculiar galaxies (29%). The DRGs at z < 1.4 with high quality spectroscopic redshifts are generally compact, with small half-light radii, and span a range in rest-frame optical properties. The spectral energy distributions for these objects differ from higher redshift DRGs: they are bluer by one magnitude in observed (I - J) color. A pure IR color selection of high redshift populations is not sufficient to identify unique populations, and other colors, or spectroscopic redshifts are needed to produce homogeneous samples 16. The bright end of the galaxy luminosity function at z ~ 7: before the onset of mass quenching? Bowler, R A A; McLure, R J; Rogers, A B; McCracken, H J; Milvang-Jensen, B; Furusawa, H; Fynbo, J P U; Taniguchi, Y; Afonso, J; Bremer, M N; Fevre, O Le 2013-01-01 We present the results of a new search for bright star-forming galaxies at z ~ 7 within the UltraVISTA DR2 and UKIDSS UDS DR10 data, which together provide 1.65 sq deg of near-infrared imaging with overlapping optical and Spitzer data. Using a full photo-z analysis to identify high-z galaxies and reject contaminants, we have selected a sample of 34 luminous (-22.7 < M_UV < -21.2) galaxies with the 6.5 < z < 7.5. Crucially, the deeper imaging provided by UltraVISTA DR2 confirms all of the robust objects previously uncovered by Bowler et al. (2012), validating our selection technique. Our sample includes the most massive galaxies known at z ~ 7, with M_* ~ 10^{10} M_sun, and the majority are resolved, consistent with larger sizes (r_{1/2} ~ 1 - 1.5 kpc) than displayed by less massive galaxies. From our final sample, we determine the form of the bright end of the rest-frame UV galaxy luminosity function (LF) at z ~ 7, providing strong evidence that the bright end of the z = 7 LF does not decline as s... 17. Ultraviolet number counts of galaxies from Swift UV/Optical Telescope deep imaging of the Chandra Deep Field South Hoversten, E A; Berk, D E Vanden; Koch, T S; Breeveld, A A; Curran, P A; Hinshaw, D A; Marshall, F E; Roming, P W A; Siegel, M H; Still, M 2009-01-01 Deep Swift UV/Optical Telescope (UVOT) imaging of the Chandra Deep Field South is used to measure galaxy number counts in three near ultraviolet (NUV) filters (uvw2: 1928 A, uvm2: 2246 A, uvw1: 2600 A) and the u band (3645 A). UVOT observations cover the break in the slope of the NUV number counts with greater precision than the number counts by the Hubble Space Telescope (HST) Space Telescope Imaging Spectrograph (STIS) and the Galaxy Evolution Explorer (GALEX), spanning a range from 21 < m_AB < 25. Number counts models confirm earlier investigations in favoring models with an evolving galaxy luminosity function. 18. Faint submillimeter galaxies revealed by multifield deep ALMA observations: number counts, spatial clustering, and a dark submillimeter line emitter Ono, Yoshiaki; Ouchi, Masami; Momose, Rieko [Institute for Cosmic Ray Research, The University of Tokyo, Kashiwa, Chiba 277-8582 (Japan); Kurono, Yasutaka, E-mail: ono@icrr.u-tokyo.ac.jp [Joint ALMA Observatory, Alonso de Cordova 3107, Vitacura, Santiago 763-0355 (Chile) 2014-11-01 We present the statistics of faint submillimeter/millimeter galaxies (SMGs) and serendipitous detections of a submillimeter/millimeter line emitter (SLE) with no multi-wavelength continuum counterpart revealed by the deep ALMA observations. We identify faint SMGs with flux densities of 0.1-1.0 mJy in the deep Band-6 and Band-7 maps of 10 independent fields that reduce cosmic variance effects. The differential number counts at 1.2 mm are found to increase with decreasing flux density down to 0.1 mJy. Our number counts indicate that the faint (0.1-1.0 mJy, or SFR{sub IR} ∼ 30-300 M {sub ☉} yr{sup –1}) SMGs contribute nearly a half of the extragalactic background light (EBL), while the remaining half of the EBL is mostly contributed by very faint sources with flux densities of <0.1 mJy (SFR{sub IR} ≲ 30 M {sub ☉} yr{sup –1}). We conduct counts-in-cells analysis with multifield ALMA data for the faint SMGs, and obtain a coarse estimate of galaxy bias, b {sub g} < 4. The galaxy bias suggests that the dark halo masses of the faint SMGs are ≲ 7 × 10{sup 12} M {sub ☉}, which is smaller than those of bright (>1 mJy) SMGs, but consistent with abundant high-z star-forming populations, such as sBzKs, LBGs, and LAEs. Finally, we report the serendipitous detection of SLE-1, which has no continuum counterparts in our 1.2 mm-band or multi-wavelength images, including ultra deep HST/WFC3 and Spitzer data. The SLE has a significant line at 249.9 GHz with a signal-to-noise ratio of 7.1. If the SLE is not a spurious source made by the unknown systematic noise of ALMA, the strong upper limits of our multi-wavelength data suggest that the SLE would be a faint galaxy at z ≳ 6. 19. Biases on cosmological parameter estimators from galaxy cluster number counts Penna-Lima, M; Wuensche, C A 2013-01-01 The abundance of galaxy clusters is becoming a standard cosmological probe. In particular, Sunyaev-Zel'dovich (SZ) surveys are promising probes of the Dark Energy (DE) equation of state (eqos), given their ability to find distant clusters and provide estimates for their mass. However, current SZ catalogs contain tens to hundreds of objects. In this case, it is not guaranteed that maximum likelihood (ML) estimators of cosmological parameters are unbiased. In this work we study estimators from cluster abundance for some cosmological parameters. We derive an unbinned likelihood for cluster abundance, showing that it is equivalent to the one commonly used in the literature. We use the Monte Carlo (MC) approach to determine the presence of bias using this likelihood and its behavior with both area and depth of the survey, and the number of cosmological parameters fitted simultaneously. Assuming perfect knowledge on mass and redshift, we obtain that some estimators have non negligible biases. For example, the bias ... 20. Herschel and SCUBA-2 imaging and spectroscopy of a bright, lensed submillimetre galaxy at z = 2.3 Ivison, R. J.; Swinbank, A. M.; Swinyard, B.; Smail, I.; Pearson, C. P.; Rigopoulou, D.; Polehampton, E.; Baluteau, J. -P.; Barlow, M.J.; Blain, A. W.; Bock, J.; Clements, D.L.; Coppin, K.; Cooray, A.; Danielson, A. 2010-01-01 We present a detailed analysis of the far-infrared (-IR) properties of the bright, lensed, z = 2.3, submillimetre-selected galaxy (SMG), SMM J2135-0102 (hereafter SMM J2135), using new observations with Herschel, SCUBA-2 and the Very Large Array (VLA). These data allow us to constrain the galaxy's spectral energy distribution (SED) and show that it has an intrinsic rest-frame 8-1000-μm luminosity, Lbol, of (2.3±0.2) × 1012 and a likely star-formation rate (SFR) of ~400 yr-1. The galaxy sits... 1. Spectroscopic Surface Brightness Fluctuations: a new method to analyze the stellar population content of galaxies Walcher, C. Jakob; Mitzkus, Martin; Roth, Martin; Dreizler, Stefan 2015-08-01 Rare luminous phases of stellar evolution are important scientific targets because our understanding of them strongly influences what physical parameters we can recover from integrated spectra. (TP-)AGB stars have been the focus of much attention over the last decade, as their flux contribution to the spectra of intermediate age stellar populations is highly uncertain. We here present a new approach to this problem, which relies on Surface Brightness Fluctuations (SBF) with high spectral resolution - a domain that is opening up for the first time thanks to the new MUSE integral field unit at the VLT. We will present the SSBF technique, illustrating its power through simulations. We will then present the analysis of dedicated data obtained with MUSE, providing new benchmark constraints on the luminous stellar population of entire galaxies. 2. THROUGH THE LOOKING GLASS: BRIGHT, HIGHLY MAGNIFIED GALAXY CANDIDATES AT z {approx} 7 BEHIND A1703 Bradley, L. D.; Coe, D. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Bouwens, R. J.; Smit, R. [Leiden Observatory, Leiden University, Postbus 9513, 2300 RA Leiden (Netherlands); Zitrin, A. [School of Physics and Astronomy, Tel Aviv University, Tel Aviv 69978 (Israel); Ford, H. C.; Zheng, W. [Department of Physics and Astronomy, Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218 (United States); Illingworth, G. D. [UCO/Lick Observatory, Department of Astronomy and Astrophysics, University of California Santa Cruz, Santa Cruz, CA 95064 (United States); Benitez, N. [Instituto de Astrofisica de Andalucia (CSIC), C/Camino Bajo de Huetor 24, Granada 18008 (Spain); Broadhurst, T. J. [Department of Theoretical Physics, University of Basque Country UPV/EHU, Leioa (Spain) 2012-03-01 We report the discovery of seven strongly lensed Lyman-break galaxy (LBG) candidates at z {approx} 7 detected in Hubble Space Telescope Wide Field Camera 3 (WFC3) imaging of A1703. The brightest candidate, called A1703-zD1, has an observed (lensed) magnitude of 24.0 AB (26{sigma}) in the WFC3/IR F160W band, making it 0.2 mag brighter than the z{sub 850}-dropout candidate recently reported behind the Bullet Cluster and 0.7 mag brighter than the previously brightest known z {approx} 7.6 galaxy, A1689-zD1. With a cluster magnification of {approx}9, this source has an intrinsic magnitude of H{sub 160} = 26.4 AB, a strong z{sub 850} - J{sub 125} break of 1.7 mag, and a photometric redshift of z {approx} 6.7. Additionally, we find six other bright LBG candidates with H{sub 160}-band magnitudes of 24.9-26.4, photometric redshifts z {approx} 6.4 - 8.8, and magnifications {mu} {approx} 3-40. Stellar population fits to the Advanced Camera for Surveys, WFC3/IR, and Spitzer/Infrared Array Camera data for A1703-zD1 and A1703-zD4 yield stellar masses (0.7 - 3.0) Multiplication-Sign 10{sup 9} M{sub Sun }, stellar ages 5-180 Myr, and star formation rates {approx}7.8 M{sub Sun} yr{sup -1}, and low reddening with A{sub V} {<=} 0.7. The source-plane reconstruction of the exceptionally bright candidate A1703-zD1 exhibits an extended structure, spanning {approx}4 kpc in the z {approx} 6.7 source plane, and shows three resolved star-forming knots of radius r {approx} 0.4 kpc. 3. Count laws and projection effects in clusters of galaxies Adami, C; Comte, G 1998-01-01 We show that a 2D projection is representative of its corresponding 3D distribution at a confidence level of 90 % if it follows a King profile and if we consider the whole spatial distribution. The level is significantly lower and not decisive in the vicinity of the 2D cluster center. On another hand, if we verify the reciprocal statement of the Mattig's distribution (1958) -i.e. a flux limited sample is represented by a 0.6 slope of its count law-, we point out that, due to the usual unaccuracy of the slope determination, a slope of 0.6 is not a sufficiently strict criterion for completeness and uniformity of a sample as often used in the literature. 4. The formation and evolution of bars in low surface brightness galaxies with cold dark matter halos Mayer, L; Mayer, Lucio; Wadsley, James 2003-01-01 We perform several high resolution N-Body/SPH simulations of low surface brightness galaxies (LSBs) embedded in cold dark matter halos to study how likely is bar formation in such systems. The behavior of various collisionless galaxy models is studied both in isolation and in the presence of a large perturbing satellite. We also consider models with a dominant gaseous component in the disk. We find that in general bar formation requires disk masses at least a factor of 2 higher than those inferred for LSBs under the assumption of a normal stellar mass-to-light ratio. Low surface density stellar disks contributing less than 10% of the total virial mass are stable within NFW halos spanning a range of concentrations. However, a purely gaseous disk can form a bar even for quite low masses and for realistic temperatures provided that cooling is very efficient (we adopt an isothermal equation of state) and that the halo has a very low concentration, c < 5. The bars that form in these LSB models are shorter than ... 5. Predictions for the Counts of Faint, High-Redshift Galaxies in the Mid-Infrared Haiman, Z; Turner, E L; Haiman, Zoltan; Spergel, David N.; Turner, Edwin L. 2003-01-01 Deep mid-infrared (MIR) observations could reveal a population of faint, high-redshift (z>3) dusty starburst galaxies that are the progenitors of present-day spheroids or bulges, and are beyond the reach of current instruments. We utilize a semi-analytic galaxy formation scheme to find an extreme model for the MIR galaxy counts, designed to maximize the number of detectable sources down to a flux level of a few nJy. The model incorporates the formation of heavily dust-enshrouded stellar populations at high redshift, and is consistent with existing observations, including faint counts at 1.6um in the NICMOS Hubble Deep Field, and the upper limit on the extragalactic MIR background from TeV gamma rays. Our models predict upto 0.5 galaxies/sq.arcsec at the threshold of 100 nJy at 6um, with a comparable or larger surface density at longer MIR wavelengths. We conclude that a significant new population of high-redshift galaxies could be detected by the Space Infrared Telescope Facility (SIRTF) and Next Generation S... 6. Deep galaxy count predictions in the radio, infrared, and X-ray spectral bands Treyer, Marie-Agnes; Silk, Joseph 1993-01-01 The existence of a dominant population of strongly evolving starburst sources at moderate redshift is a plausible explanation for the excess number of faint blue galaxies detected in deep sky surveys. Multiwavelength observations at faint magnitudes would allow the existence of such a population to be confirmed. We use observed luminosity correlations and physical properties of known starburst galaxies to predict their contribution to the deep radio, infrared, and X-ray counts, as well as to the diffuse extragalactic background radiation in these various spectral bands. 7. The cosmological significance of Low Surface Brightness galaxies found in a deep blind neutral-hydrogen survey Minchin, R F; Parker, Q A; Boyce, P J; De Blok, W J G; Banks, G D; Ekers, R D; Freeman, K C; García, D A; Gibson, B K; Grossi, M; Haynes, R F; Knezek, P M; Lang, R H; Malin, D F; Price, R M; Putman, M E; Stewart, I M; Wright, A E 2004-01-01 We have placed limits on the cosmological significance of gas-rich low surface-brightness (LSB) galaxies as a proportion of the total population of gas-rich galaxies by carrying out a very deep survey (HIDEEP) for neutral hydrogen (HI) with the Parkes multibeam system. Such a survey avoids the surface-brightness selection effects that limit the usefulness of optical surveys for finding LSB galaxies. To complement the HIDEEP survey we have digitally stacked eight 1-hour R-band Tech Pan films from the UK Schmidt Telescope covering 36 square degrees of the survey area to reach a very deep isophotal limit of 26.5 R mag/sq. arcsec. At this level, we find that all of the 129 HI sources within this area have optical counterparts and that 107 of them can be identified with individual galaxies. We have used the properties of the galaxies identified as the optical counterparts of the HI sources to estimate the significance of LSB galaxies (defined to be those at least 1.5 magnitudes dimmer in effective surface-brightne... 8. A New Constraint on the Lyα Fraction of UV Very Bright Galaxies at Redshift 7 Furusawa, Hisanori; Kashikawa, Nobunari; Kobayashi, Masakazu A. R.; Dunlop, James S.; Shimasaku, Kazuhiro; Takata, Tadafumi; Sekiguchi, Kazuhiro; Naito, Yoshiaki; Furusawa, Junko; Ouchi, Masami; Nakata, Fumiaki; Yasuda, Naoki; Okura, Yuki; Taniguchi, Yoshiaki; Yamada, Toru; Kajisawa, Masaru; Fynbo, Johan P. U.; Le Fèvre, Olivier 2016-05-01 We study the extent to which very bright (-23.0\\lt {M}{UV}\\lt -21.75) Lyman-break-selected galaxies at redshifts z≃ 7 display detectable Lyα emission. To explore this issue, we obtained follow-up optical spectroscopy of 9 z≃ 7 galaxies from a parent sample of 24 z≃ 7 galaxy candidates selected from the 1.65 deg2 COSMOS-UltraVISTA and SXDS-UDS survey fields using the latest near-infrared public survey data, and new ultra-deep Subaru z‧-band imaging (which we also present and describe in this paper). Our spectroscopy yielded only one possible detection of Lyα at z = 7.168 with a rest-frame equivalent width {{EW}}0 = {3.7}-1.1+1.7 \\mathringA . The relative weakness of this line, combined with our failure to detect Lyα emission from the other spectroscopic targets, allows us to place a new upper limit on the prevalence of strong Lyα emission at these redshifts. For conservative calculation and to facilitate comparison with previous studies at lower redshifts, we derive a 1σ upper limit on the fraction of UV-bright galaxies at z≃ 7 that display {{EW}}0\\gt 50 \\mathringA , which we estimate to be \\lt 0.23. This result may indicate a weak trend where the fraction of strong Lyα emitters ceases to rise, and possibly falls between z ≃ 6 and z≃ 7. Our results also leave open the possibility that strong Lyα may still be more prevalent in the brightest galaxies in the reionization era than their fainter counterparts. A larger spectroscopic sample of galaxies is required to derive a more reliable constraint on the neutral hydrogen fraction at z∼ 7 based on the Lyα fraction in the bright galaxies. 9. Fast automated yeast cell counting algorithm using bright-field and fluorescence microscopic images Hong, Dongpyo; Lee, Gwanghee; Jung, Neon Cheol; Jeon, Moongu 2013-01-01 Background The faithful determination of the concentration and viability of yeast cells is important for biological research as well as industry. To this end, it is important to develop an automated cell counting algorithm that can provide not only fast but also accurate and precise measurement of yeast cells. Results With the proposed method, we measured the precision of yeast cell measurements by using 0%, 25%, 50%, 75% and 100% viability samples. As a result, the actual viability measured ... 10. Predictions of radio counts of star forming galaxies for SKA precursors We extended recent semi-analitycal galaxy formation models, that fitted the far- infrared (FIR) to millimeter wave luminosity functions and ultraviolet (UV) luminosity functions up to high redshifts, in order to take into account additional UV data and Hα luminosity functions. The latters are tracers of star formation in evolved galaxies at low redshifts. Using the relations between star formation rate (SFR) and radio (synchrotron and free-free) emission, we obtained predictions for the counts of star-forming galaxies down to sub-nJy fluxes. These will be very useful for the new generation of radio telescopes, thanks to which it will be possible to investigate smaller and smaller radio fluxes (down to nJy), making the detection of little SFR possible 11. THE AGN, STAR-FORMING, AND MORPHOLOGICAL PROPERTIES OF LUMINOUS IR-BRIGHT/OPTICALLY-FAINT GALAXIES We present the active galactic nucleus (AGN), star-forming, and morphological properties of a sample of 13 MIR-luminous (f 24 ∼> 700 μJy) IR-bright/optically-faint galaxies (IRBGs, f24/f R ∼> 1000). While these z ∼ 2 sources were drawn from deep Chandra fields with >200 ks X-ray coverage, only seven are formally detected in the X-ray and four lack X-ray emission at even the 2σ level. Spitzer InfraRed Spectrograph (IRS) spectra, however, confirm that all of the sources are AGN-dominated in the mid-IR, although half have detectable polycyclic aromatic hydrocarbon (PAH) emission responsible for ∼25% of their mid-infrared flux density. When combined with other samples, this indicates that at least 30%-40% of luminous IRBGs have star formation rates in the ultraluminous infrared galaxy (ULIRG) range (∼100-2000 Msun yr-1). X-ray hardness ratios and MIR to X-ray luminosity ratios indicate that all members of the sample contain heavily X-ray obscured AGNs, 80% of which are candidates to be Compton thick. Furthermore, the mean X-ray luminosity of the sample, log L2-10keV(erg s-1) ∼44.6, indicates that these IRBGs are Type 2 QSOs, at least from the X-ray perspective. While those sources most heavily obscured in the X-ray are also those most likely to display strong silicate absorption in the mid-IR, silicate absorption does not always accompany X-ray obscuration. Finally, ∼70% of the IRBGs are merger candidates, a rate consistent with that of sub-mm galaxies (SMGs), although SMGs appear to be physically larger than IRBGs. These characteristics are consistent with the proposal that these objects represent a later, AGN-dominated, and more relaxed evolutionary stage following soon after the star-formation-dominated one represented by the SMGs. 12. Star formation and the interstellar medium in low surface brightness galaxies; 2, Deep CO observations of low surface brightness disk galaxies De Blok, W J G 1998-01-01 We present deep, pointed$^{12}$CO($J=2-1$) observations of three late-type LSB galaxies. The beam-size was small enough that we could probe different environments (\\HI maximum, \\HI mininum, star forming region) in these galaxies. No CO was found at any of the positions observed. We argue that the implied lack of molecular gas is real and not caused by conversion factor effects. The virtual absence of a molecular phase may explain the very low star formation rates in these galaxies. 13. Populations of Bright X-ray Sources in the Starburst Galaxies NGC 4038/4039 Xi-Wei Liu; Xiang-Dong Li 2007-01-01 Assuming a naive star formation history,we construct synthetic X-ray source populations.using a population synthesis code,for comparison with the observed X-ray luminosity function (XLF) of the interacting galaxies NGC 4038/4039.We have included highand intermediate-mass X-ray binaries.young rotation-powered pulsars and fallback disk-fed black holes in modeling the bright X-ray sources detected.We find that the majority of the X-ray sources are likely to be intermediate-mass X-ray binaries.but for typical binary evolution parameters.the predicted XLF seems to be steeper than observed.We note that the shape of the XLFs depends critically on the existence of XLF break for young populations.and suggest super-Eddington accretion luminosities or the existence of intermediate-mass black holes to account for the high luminosity end and the slope of the XLF in NGC 4038/4039. 14. A comprehensive analysis of the hard X-ray spectra of bright Seyfert galaxies Lubinski, P; Gibaud, L; Paltani, S; Papadakis, I E; Ricci, C; Soldi, S; Türler, M; Walter, R; Zdziarski, A A 2016-01-01 Hard X-ray spectra of 28 bright Seyfert galaxies observed with INTEGRAL were analyzed together with the X-ray spectra from XMM-Newton, Suzaku and RXTE. These broad-band data were fitted with a model assuming a thermal Comptonization as a primary continuum component. We tested several model options through a fitting of the Comptonized continuum accompanied by a complex absorption and a Compton reflection. Both the large data set used and the model space explored allowed us to accurately determine a mean temperature kTe of the electron plasma, the Compton parameter y and the Compton reflection strength R for the majority of objects in the sample. Our main finding is that a vast majority of the sample (20 objects) is characterized by kTe 200 keV. The median kTe for entire sample is 48(-14,+57) keV. The distribution of the y parameter is bimodal, with a broad component centered at ~0.8 and a narrow peak at ~1.1. A complex, dual absorber model improved the fit for all data sets, compared to a simple absorption mo... 15. Detection of an ultra-bright submillimeter galaxy behind the Small Magellanic Cloud Takekoshi, Tatsuya; Minamidani, Tetsuhiro; Kohno, Kotaro; Oogi, Taira; Sorai, Kazuo; Habe, Asao; Ezawa, Hajime; Oshima, Tai; Scott, Kimberly S; Austermann, Jason E; Komugi, Shinya; Tosaki, Tomoka; Mizuno, Norikazu; Muller, Erik; Kawamura, Akiko; Onishi, Toshikazu; Fukui, Yasuo; Matsuo, Hiroshi; Aretxaga, Itziar; Hughes, David H; Kawabe, Ryohei; Wilson, Grant W; Yun, Min S 2013-01-01 We report the discovery of a new ultra-bright submillimeter galaxy (SMG) behind the Small Magellanic Cloud (SMC). This SMG is detected as a 43.3+-8.4 mJy point source (MM J01071-7302, hereafter MMJ0107) in the 1.1 mm continuum survey of the SMC by AzTEC on the ASTE telescope. MMJ0107 is also detected in the radio (843 MHz), Herschel/SPIRE, Spitzer MIPS 24 {\\mu}m, all IRAC bands, Wide-field Infrared Survey Explorer, and near-infrared (J, H, KS). We find an optical (U, B, V) source, which might be the lensing object, at a distance of 1.4 arcsec from near-infrared and IRAC sources. Photometric redshift estimates for the SMG using representative spectral energy distribution templates show the redshifts of 1.4-3.9. We estimate total far-infrared luminosity of (0.3-2.2)x10^14 {\\mu}^-1 L_sun and a star formation rate of 5600-39, 000 {\\mu}^-1 M_sun yr^-1, where {\\mu} is the gravitational magnification factor. This apparent extreme star formation activity is likely explained by a highly magnified gravitational lens sy... 16. DETECTION OF AN ULTRA-BRIGHT SUBMILLIMETER GALAXY BEHIND THE SMALL MAGELLANIC CLOUD We report the discovery of a new ultra-bright submillimeter galaxy (SMG) behind the Small Magellanic Cloud (SMC). This SMG is detected as a 43.3 ± 8.4 mJy point source (MM J01071–7302, hereafter MMJ0107) in the 1.1 mm continuum survey of the SMC by AzTEC on the ASTE telescope. MMJ0107 is also detected in the radio (843 MHz), Herschel/SPIRE, Spitzer MIPS 24 μm, all IRAC bands, Wide-field Infrared Survey Explorer, and near-infrared (J, H, KS ). We find an optical (U, B, V) source, which might be the lensing object, at a distance of 1.''4 from near-infrared and IRAC sources. Photometric redshift estimates for the SMG using representative spectral energy distribution templates show the redshifts of 1.4-3.9. We estimate total far-infrared luminosity of (0.3-2.2) × 1014 μ–1 L☉ and a star formation rate of 5600-39, 000 μ–1 M☉ yr–1, where μ is the gravitational magnification factor. This apparent extreme star formation activity is likely explained by a highly magnified gravitational lens system 17. DETECTION OF AN ULTRA-BRIGHT SUBMILLIMETER GALAXY BEHIND THE SMALL MAGELLANIC CLOUD Takekoshi, Tatsuya; Minamidani, Tetsuhiro; Sorai, Kazuo; Habe, Asao [Department of Cosmosciences, Graduate School of Science, Hokkaido University, Sapporo 060-0810 (Japan); Tamura, Yoichi; Kohno, Kotaro [Institute of Astronomy, University of Tokyo, Osawa, Mitaka, Tokyo 181-0015 (Japan); Oogi, Taira [Department of Physics, Faculty of Science, Hokkaido University, Sapporo 060-0810 (Japan); Ezawa, Hajime; Komugi, Shinya; Mizuno, Norikazu; Muller, Erik; Kawamura, Akiko [Chile Observatory, National Astronomical Observatory, Mitaka, Tokyo 181-8588 (Japan); Oshima, Tai [Nobeyama Radio Observatory, National Astronomical Observatory of Japan, Minamimaki, Minamisaku, Nagano 384-1305 (Japan); Scott, Kimberly S. [North American ALMA Science Center, National Radio Astronomy Observatory, Charlottesville, VA 22903 (United States); Austermann, Jason E. [Center for Astrophysics and Space Astronomy, University of Colorado, Boulder, CO 80309 (United States); Tosaki, Tomoka [Joetsu University of Education, Joetsu, Niigata 943-8512 (Japan); Onishi, Toshikazu [Department of Physical Science, Osaka Prefecture University, Gakuen 1-1, Sakai, 599-8531 Osaka (Japan); Fukui, Yasuo [Department of Astrophysics, Nagoya University, Chikusa-ku, Nagoya 464-8602 (Japan); Matsuo, Hiroshi [Advanced Technology Center, National Astronomical Observatory of Japan, Mitaka, Tokyo 181-8588 (Japan); Aretxaga, Itziar [Instituto Nacional de Astrofisica, Optica y Electronica (INAOE), 72000 Puebla (Mexico); and others 2013-09-10 We report the discovery of a new ultra-bright submillimeter galaxy (SMG) behind the Small Magellanic Cloud (SMC). This SMG is detected as a 43.3 {+-} 8.4 mJy point source (MM J01071-7302, hereafter MMJ0107) in the 1.1 mm continuum survey of the SMC by AzTEC on the ASTE telescope. MMJ0107 is also detected in the radio (843 MHz), Herschel/SPIRE, Spitzer MIPS 24 {mu}m, all IRAC bands, Wide-field Infrared Survey Explorer, and near-infrared (J, H, K{sub S} ). We find an optical (U, B, V) source, which might be the lensing object, at a distance of 1.''4 from near-infrared and IRAC sources. Photometric redshift estimates for the SMG using representative spectral energy distribution templates show the redshifts of 1.4-3.9. We estimate total far-infrared luminosity of (0.3-2.2) Multiplication-Sign 10{sup 14} {mu}{sup -1} L{sub Sun} and a star formation rate of 5600-39, 000 {mu}{sup -1} M{sub Sun} yr{sup -1}, where {mu} is the gravitational magnification factor. This apparent extreme star formation activity is likely explained by a highly magnified gravitational lens system. 18. Type-II surface brightness profiles in edge-on galaxies produced by flares Borlaff, Alejandro; Beckman, John; Font, Joan 2016-01-01 Previous numerical studies had apparently ruled out the possibility that flares in galaxy discs could give rise to the apparent breaks in their luminosity profiles when observed edge-on. However the studies have not, until now, analyzed this hypothesis systematically using realistic models for the disc, the flare, and the bulge. We revisit this theme by analyzing a series of models which sample a wide range of observationally based structural parameters for these three components. We have considered realistic distributions of bulge to disc ratios, morphological parameters of bulges and discs, vertical scale heights of discs and their radial gradients defining the flare for different morphological types and stellar mass bins, based on observations. The surface brightness profiles for the face-on and edge-on views of each model were simulated to find out whether the flared disc produces a Type-II break in the disc profile when observed edge-on, and if so under what conditions. Contrary to previous claims, we fi... 19. Bright Galaxies at Hubble's Detection Frontier: The redshift z~9-10 BoRG pure-parallel survey Trenti, Michele 2014-10-01 Hubble/WFC3 observations transformed our view of early galaxy formation by building reliable samples of galaxies out to redshift z 8, 700 Myr after the Big Bang and hinting at a dramatic evolution in properties at yet earlier times. From z 8 to z 10 { 200Myr} the luminosity density seems to decrease by a factor ten, but bright galaxies may remain relatively common, based on the four z>9 objects detected so far with m_ABsuccessful Cycle 17 & 19 Brightest of Reionizing Galaxies {BoRG} Survey, which found the largest sample of L>L* galaxies at z 8. BoRG[z8] demonstrated, by adding constraints from the Ultra Deep Field {UDF}, that the luminosity function follows a Schechter form, as at lower z, but with a steeper faint-end slope, leading to a photon production sufficient to complete reionization. BoRG[z9-10] will similarly complement the UDF and Frontier Fields datasets by imaging 550 arcmin^2 over 120 sightlines in five WFC3 bands {F350LP, F105W, F125W, F140W, F160W}. Besides twenty new catches at z>9, we will double {from 60 to 120} the number of bright z 8 galaxies within reach of spectroscopy, to tighten constraints on Ly-alpha emission and reionization obtained by our BoRG@Keck follow-up. This new public dataset will reveal the connection between massive dark matter halos and formation of first galaxies, and create a legacy of rare targets for JWST 20. Spitzer/IRAC Imaging of Exceptionally Bright Cluster-Lensed Submillimeter Galaxies Discovered by the Herschel Lensing Survey Egami, Eiichi; Ebeling, Harald; Rawle, Timothy; Clement, Benjamin; Walth, Gregory; Pereira, Maria; Richard, Johan; Kneib, Jean-Paul 2012-12-01 Over the last few years, discoveries of exceptionally bright (e.g., observed S_peak > 100 mJy in the Herschel/SPIRE bands) gravitationally lensed submillimeter galaxies (SMGs) have generated great excitement. This is because these gravitationally lensed SMGs are so bright that they enable us to perform a variety of follow-up observations using a suite of observing facilities in the submillimeter, millimeter, and radio now available on the ground. Using Herschel, our team has been conducting a survey of such bright lensed galaxies in the fields of massive galaxy clusters: The Herschel Lensing Survey (HLS)'' (PI: Egami; 419 hours). This large Herschel program targets a total of 581 X-ray/SZ-selected massive clusters, and is currently 80% complete. Cluster lenses are often more powerful than galaxy lenses, producing larger magnifications. For example, typical magnification factors for galaxy-lensed Herschel sources are x10 or less while cluster-lensed systems can often produce magnification factors of x20-30 and even above x100. Cluster lenses will therefore allow us to detect and study intrinsically less-luminous and/or more distant sources with the ability to provide a view of finer-scale (i.e., sub-kpc) structures. Here, we propose to conduct Spitzer/IRAC imaging of 56 bright lensed SMG candidates we have identified in the ~470 HLS cluster fields observed so far. The main scientific goal is twofold: (1) to locate the underlying stellar component, and (2) to study its properties (e.g., stellar mass, specific star-formation rate) by constraining the rest-frame near-infrared SED and comparing with the Herschel and other submillimeter/millimeter data (e.g., SMA, PdB, ALMA, etc.). These rare bright lensed SMGs will allow us to probe the population of heavily dust-obscured vigorously star-forming galaxies at high redshift (z>1), which is thought to play an important role in the cosmic star-formation history of the Universe and yet has been difficult to study due to the 1. Star Counts in the Globular Cluster ω Centauri. I. Bright Stellar Components Castellani, V.; Calamida, A.; Bono, G.; Stetson, P. B.; Freyhammer, L. M.; Degl'Innocenti, S.; Moroni, P. Prada; Monelli, M.; Corsi, C. E.; Nonino, M.; Buonanno, R.; Caputo, F.; Castellani, M.; Dall'Ora, M.; Del Principe, M.; Ferraro, I.; Iannicola, G.; Piersimoni, A. M.; Pulone, L.; Vuerli, C. 2007-07-01 We present a photometric investigation on HB, RGB, and MSTO stars in ω Cen=NGC 5139. The center of the cluster was covered with a mosaic of F435W, F625W, and F658N band data collected with HST ACS. The outer reaches were covered with a mosaic of U-, B-, V-, and I-band data collected with the 2.2 m ESO/MPI telescope. The final catalog includes ~1.7 million stars. We identified more than 3200 likely HB stars, the largest sample ever collected in a globular cluster. We found that the HB morphology changes with the radial distance from the cluster center. The relative number of extreme HB stars decreases from ~30% to ~21% when moving from the center toward the outer reaches of the cluster, while the fraction of less hot HB stars increases from ~62% to ~72%. The comparison between theory and observations indicates that the empirical star counts of HB stars are on average larger (30%-40%) than predicted by canonical evolutionary models. Moreover, the rate of HB stars is ~43% larger than the MSTO rate. We also compared theory and observations by assuming a mix of stellar populations made with 70% of canonical He (Y=0.23) stars and 30% of He-enhanced (Y=0.33, 0.42) stars. We found that the observed RG/MSTO ratio agrees with the predicted lifetimes of He-mixed stellar populations. The discrepancy between theory and observations decreases by a factor of 2 when compared with rates predicted by canonical He content models, but still 15%-25% (Y=0.42) and 15%-20% (Y=0.33) higher than observed. Furthermore, the ratios between HB and MSTO star counts are ~24% (Y=0.42) and 30% (Y=0.33) larger than predicted lifetime ratios. During the revision of this manuscript, Vittorio Castellani passed away on 2006 May 19. His suggestions, ideas, and personality will be greatly missed. Based on data obtained from the ESO Science Archive Facility and the Hubble Space Telescope Archive Facility. 2. Multicolour Optical Surface Brightness Profiles Decomposition of the Seyfert Galaxies III Zw 2, Mrk 506 and Mrk 509 Slavcheva-Mihova, L.; Mihov, B.; Petrov, G.; Kopchev, V. 2006-01-01 We present the results of the UBVRcIc surface brightness profiles decomposition of the Seyfert galaxies III Zw 2, Mrk 506 and Mrk 509. The profiles were modelled as a sum of a Gaussian, a Sersic law and an exponent. A Ferrers bar and a Gaussian ring were added to the model profiles of III Zw 2 and Mrk 506, respectively. The parameters and the total magnitudes of the structural components were derived. 3. Relating basic properties of bright early-type dwarf galaxies to their location in Abell 901/902 Barazza, F D; Gray, M E; Jogee, S; Balogh, M; McIntosh, D H; Bacon, D; Barden, M; Bell, E F; Boehm, A; Caldwell, J A R; Haeussler, B; Heiderman, A; Heymans, C; van Kampen, K Jahnke E; Lane, K; Marinova, I; Meisenheimer, K; Peng, C Y; Sánchez, S F; Taylor, A; Wisotzki, L; Zheng, X 2009-01-01 We present a study of the population of bright early-type dwarf galaxies in the multiple-cluster system Abell 901/902. We use data from the STAGES survey and COMBO-17 to investigate the relation between the color and structural properties of the dwarfs and their location in the cluster. The definition of the dwarf sample is based on the central surface brightness and includes galaxies in the luminosity range -16 >= M_B <~-19 mag. Using a fit to the color magnitude relation of the dwarfs, our sample is divided into a red and blue subsample. We find a color-density relation in the projected radial distribution of the dwarf sample: at the same luminosity dwarfs with redder colors are located closer to the cluster centers than their bluer counterparts. Furthermore, the redder dwarfs are on average more compact and rounder than the bluer dwarfs. These findings are consistent with theoretical expectations assuming that bright early-type dwarfs are the remnants of transformed late-type disk galaxies involving pro... 4. High redshift galaxies in the ALHAMBRA survey: I. selection method and number counts based on redshift PDFs Viironen, K; López-Sanjuan, C; Varela, J; Chaves-Montero, J; Cristóbal-Hornillos, D; Molino, A; Fernández-Soto, A; Ascaso, B; Cenarro, A J; Cerviño, M; Cepa, J; Ederoclite, A; Márquez, I; Masegosa, J; Moles, M; Oteo, I; Pović, M; Aguerri, J A L; Alfaro, E; Aparicio-Villegas, T; Benítez, N; Broadhurst, T; Cabrera-Caño, J; Castander, J F; Del Olmo, A; Delgado, R M González; Husillos, C; Infante, L; Martínez, V J; Perea, J; Prada, F; Quintana, J M 2015-01-01 Context. Most observational results on the high redshift restframe UV-bright galaxies are based on samples pinpointed using the so called dropout technique or Ly-alpha selection. However, the availability of multifilter data allows now replacing the dropout selections by direct methods based on photometric redshifts. In this paper we present the methodology to select and study the population of high redshift galaxies in the ALHAMBRA survey data. Aims. Our aim is to develop a less biased methodology than the traditional dropout technique to study the high redshift galaxies in ALHAMBRA and other multifilter data. Thanks to the wide area ALHAMBRA covers, we especially aim at contributing in the study of the brightest, less frequent, high redshift galaxies. Methods. The methodology is based on redshift probability distribution functions (zPDFs). It is shown how a clean galaxy sample can be obtained by selecting the galaxies with high integrated probability of being within a given redshift interval. However, reach... 5. HST photometry of dwarf elliptical galaxies in Coma, and an explanation for the alleged structural dichotomy between dwarf and bright elliptical galaxies Graham, A W; Graham, Alister W.; Guzman, Rafael 2003-01-01 We have analyzed archival HST F606W images of 18 dwarf elliptical (dE) galaxy candidates in the Coma Cluster. We model the full radial extent of their light- profiles by simultaneously fitting a PSF-convolved Sersic R^(1/n) model and, when necessary, either a central point-source or a central PSF-convolved Gaussian. The luminosities of the central component L_nuc scale with the host galaxy luminosity L_gal such that L_nuc = 10^(4.76 +/- 0.10) (L_gal/10^7)^(0.87 +/- 0.26). The underlying host galaxies display systematic departures from an exponential model that are correlated with the model-independent host galaxy luminosity and are not due to biasing from the nuclear component. The Pearson correlation coefficient between log(n) and central galaxy surface brightness mu_0 (excluding the flux from extraneous central components) is -0.83 at a significance level of 99.99%. The Pearson correlation coefficient between the logarithm of the Sersic index n' and the host galaxy magnitude is -0.77 at a significance of 9... 6. Extra-galactic background light measurements from the far-UV to the far-IR from deep ground and space-based galaxy counts Driver, Simon P; Davies, Luke J; Robotham, Aaron S G; Wright, Angus H; Windhorst, Rogier A; Cohen, Seth; Emig, Kim; Jansen, Rolf A; Dunne, Loretta 2016-01-01 We combine wide and deep galaxy number-count data from GAMA, COSMOS/G10, HST ERS, HST UVUDF and various near-, mid- and far- IR datasets from ESO, Spitzer and Herschel. The combined data range from the far-UV (0.15microns) to far-IR (500microns), and in all cases the contribution to the integrated galaxy light (IGL) of successively fainter galaxies converges. Using a simple spline fit, we derive the IGL and the extrapolated-IGL in all bands. We argue undetected low surface brightness galaxies and intra-cluster/group light is modest, and that our extrapolated-IGL measurements are an accurate representation of the extra-galactic background light. Our data agree with most earlier IGL estimates and with direct measurements in the far-IR, but disagree strongly with direct estimates in the optical. Close agreement between our results and recent very high-energy experiments (H.E.S.S. and MAGIC), suggest that there may be an additional foreground affecting the direct estimates. The most likely culprit could be the ad... 7. Bright radio sources at 178 MHz: flux densities, optical identifications and the cosmological evolution of powerful radio galaxies In order to correct the biases introduced into the 3CR catalogue by confusion and partial resolution, a revised sample of bright sources has been defined at 178 MHz. The sample is 96 per cent complete to a flux-density limit of 10 Jy for sources smaller than 10 arcmin. The incompleteness of 3CR to sources of larger angular size has also been reduced. 96 per cent of the sources in the revised sample are identified optically, 71 and 25 per cent with galaxies and quasars, respectively. The radio-galaxy population shows strong space-density evolution for luminosities in excess of approx. 10sup(26.5) W Hz-1 sr-1 at 178 MHz (redshifts >approx. equal to 0.2); the evolutionary properties of galaxies and quasars of the same luminosity and redshift are very similar. (author) 8. Extremely-bright submillimeter galaxies beyond the Lupus-I star-forming region Tamura, Y; Shimajiri, Y; Tsukagoshi, T; Nakajima, Y; Oasa, Y; Wilner, D J; Chandler, C J; Saigo, K; Tomida, K; Yun, M S; Taniguchi, A; Kohno, K; Hatsukade, B; Aretxaga, I; Austermann, J E; Dickman, R; Ezawa, H; Goss, W M; Hayashi, M; Hughes, D H; Hiramatsu, M; Inutsuka, S; Ogasawara, R; Ohashi, N; Oshima, T; Scott, K S; Wilson, G W 2015-01-01 We report detections of two candidate distant submillimeter galaxies (SMGs), MM J154506.4$-$344318 and MM J154132.7$-$350320, which are discovered in the AzTEC/ASTE 1.1 mm survey toward the Lupus-I star-forming region. The two objects have 1.1 mm flux densities of 43.9 and 27.1 mJy, and have Herschel/SPIRE counterparts as well. The Submillimeter Array counterpart to the former SMG is identified at 890$\\mu$m and 1.3 mm. Photometric redshift estimates using all available data from the mid-infrared to the radio suggest that the redshifts of the two SMGs are$z_{\\rm photo} \\simeq$4-5 and 3, respectively. Near-infrared objects are found very close to the SMGs and they are consistent with low-$z$ellipticals, suggesting that the high apparent luminosities can be attributed to gravitational magnification. The cumulative number counts at$S_{\\rm 1.1mm} \\ge 25$mJy, combined with other two 1.1-mm brightest sources, are$0.70 ^{+0.56}_{-0.34}$deg$^{-2}$, which is consistent with a model prediction that accounts for ... 9. BRIGHT Lights, BIG City: Massive Galaxies, Giant Ly-A Nebulae, and Proto-Clusters van Breugel, W; Reuland, M; de Vries, W; Stanford, A; Dey, A; Kurk, J; Venemans, B; Rottgering, H; Miley, G; De Breuck, C; Dopita, M; Sutherland, R; Bland-Hawthorn, J 2002-08-01 High redshift radio galaxies are great cosmological tools for pinpointing the most massive objects in the early Universe: massive forming galaxies, active super-massive black holes and proto-clusters. They report on deep narrow-band imaging and spectroscopic observations of several z > 2 radio galaxy fields to investigate the nature of giant Ly-{alpha} nebulae centered on the galaxies and to search for over-dense regions around them. They discuss the possible implications for our understanding of the formation and evolution of massive galaxies and galaxy clusters. 10. UBVRI photometry of bright GB/GB2 radio galaxies and quasars Photoelectric UBVRI observations of 25 radio galaxies brighter than V ∼ 17 mag, and 14 quasars and other stellar objects brighter than V ∼ 18 mag are presented and discussed. These objects coincide with the GB/GB2 radio sources, extensively observed with the VLA at 1465 MHz. Galaxy broad-band colours confirm that most of these galaxies are giant ellipticals. (author) 11. zCOSMOS-10k-bright spectroscopic sample. The bimodality in the galaxy stellar mass function : Exploring its evolution with redshift Pozzetti, L.; Bolzonella, M.; Zucca, E.; Zamorani, G.; Lilly, S.; Renzini, A.; Moresco, M.; Mignoli, M.; Cassata, P.; Tasca, L.; Lamareille, F.; Maier, C.; Meneux, B.; Halliday, C.; Oesch, P.; Vergani, D.; Caputi, K.; Kovac, K.; Cimatti, A.; Cucciati, O.; Iovino, A.; Peng, Y.; Carollo, M.; Contini, T.; P. Kneib, J.; Le F'evre, O.; Mainieri, V.; Scodeggio, M.; Bardelli, S.; Bongiorno, A.; Coppa, G.; de la Torre, S.; de Ravel, L.; Franzetti, P.; Garilli, B.; Kampczyk, P.; Knobel, C.; F. Le Borgne, J.; Le Brun, V.; Pello, R.; Perez Montero, E.; Ricciardelli, E.; D. Silverman, J.; Tanaka, M.; Tresse, L.; Abbas, U.; Bottini, D.; Cappi, A.; Guzzo, L.; M. Koekemoer, A.; Leauthaud, A.; Maccagni, D.; Marinoni, C.; J. McCracken, H.; Memeo, P.; Porciani, C.; Scaramella, R.; Scarlata, C.; Scoville, N. 2010-01-01 We present the galaxy stellar mass function (GSMF) to redshift z similar or equal to 1, based on the analysis of about 8500 galaxies with I <22.5 (AB mag) over 1.4 deg(2), which are part of the zCOSMOS-bright 10k spectroscopic sample. We investigate the total GSMF, as well as the contributions of ea 12. Sleeping Giants? - X-ray search for low-luminosity AGN candidates in nearby optically bright galaxies Kalcheva, Ivayla E 2014-01-01 In this Master's project, the X-ray nuclear properties of a sample of bright nearby galaxies are explored. This is done by matching their comprehensive optical spectroscopic classification to the latest available XMM-Newton catalogue - 3XMM-DR4. The good coverage (approx. 38 per cent) ensures that a statistically representative sample is investigated. All nuclear and morphological subsets found within the original sample of 486 galaxies are encompassed, but early-type galaxies and galaxies with optical features characteristic for active galactic nuclei (AGN) are favoured. The results from the investigation of the properties of our cross-matched sample are overall consistent with the presence of a large fraction of X-ray - detected low-luminosity AGN (LLAGN). The X-ray - detected galaxies within our HII and transition-LINER subsets are of particular interest, as they could harbour LLAGN missed by optical spectroscopic selection. The properties of these nuclei are explored by X-ray spectral fitting of available... 13. Blending bias impacts the host halo masses derived from a cross-correlation analysis of bright sub-millimetre galaxies Cowley, William I; Baugh, Carlton M; Cole, Shaun; Wilkinson, Aaron 2016-01-01 Placing bright sub-millimetre galaxies (SMGs) within the broader context of galaxy formation and evolution requires accurate measurements of their clustering, which can constrain the masses of their host dark matter halos. Recent work has shown that the clustering measurements of these galaxies may be affected by a blending bias,' which results in the angular correlation function of the sources extracted from single-dish imaging surveys being boosted relative to that of the underlying galaxies. This is due to confusion introduced by the coarse angular resolution of the single-dish telescope and could lead to the inferred halo masses being significantly overestimated. We investigate the extent to which this bias affects the measurement of the correlation function of SMGs when it is derived via a cross-correlation with a more abundant galaxy population. We find that the blending bias is essentially the same as in the auto-correlation case and conclude that the best way to reduce its effects is to calculate the... 14. Galaxy halo truncation and Giant Arc Surface Brightness Reconstruction in the Cluster MACSJ1206.2-0847 Eichner, Thomas; Suyu, Sherry H; Halkola, Aleksi; Umetsu, Keiichi; Zitrin, Adi; Coe, Dan; Monna, Anna; Rosati, Piero; Grillo, Claudio; Balestra, Italo; Postman, Marc; Koekemoer, Anton; Zheng, Wei; H\\ost, Ole; Lemze, Doron; Broadhurst, Tom; Moustakas, Leonidas; Bradley, Larry; Molino, Alberto; Nonino, Mario; Mercurio, Amata; Scodeggio, Marco; Bartelmann, Matthias; Benitez, Narciso; Bouwens, Rychard; Donahue, Megan; Infante, Leopoldo; Jouvel, Stephanie; Kelson, Daniel; Lahav, Ofer; Medezinski, Elinor; Melchior, Peter; Merten, Julian; Riess, Adam 2013-01-01 In this work we analyze the mass distribution of MACSJ1206.2-0847, especially focusing on the halo properties of its cluster members. The cluster appears relaxed in its X-ray emission, but has significant amounts of intracluster light which is not centrally concentrated, suggesting that galaxy-scale interactions are still ongoing despite the overall relaxed state. The cluster lenses 12 background galaxies into multiple images and one galaxy at$z=1.033$into a giant arc and its counterimage. The multiple image positions and the surface brightness distribution (SFB) of the arc which is bent around several cluster members are sensitive to the cluster galaxy halo properties. We model the cluster mass distribution with a NFW profile and the galaxy halos with two parameters for the mass normalization and extent of a reference halo assuming scalings with their observed NIR--light. We match the multiple image positions at an r.m.s. level of$0.85\\arcsec$and can reconstruct the SFB distribution of the arc in several... 15. GALAXY HALO TRUNCATION AND GIANT ARC SURFACE BRIGHTNESS RECONSTRUCTION IN THE CLUSTER MACSJ1206.2-0847 Eichner, Thomas; Seitz, Stella; Monna, Anna [Universitaets-Sternwarte Muenchen, Scheinerstr. 1, D-81679 Muenchen (Germany); Suyu, Sherry H. [Department of Physics, University of California, Santa Barbara, CA 93106 (United States); Halkola, Aleksi [Institute of Medical Engineering, University of Luebeck, Ratzeburger Allee 160 23562 Luebeck (Germany); Umetsu, Keiichi [Institute of Astronomy and Astrophysics, Academia Sinica, P.O. Box 23-141, Taipei 10617, Taiwan (China); Zitrin, Adi [Institut fuer Theoretische Astrophysik, ZAH, Albert-Ueberle-Strasse 2, D-69120 Heidelberg (Germany); Coe, Dan; Postman, Marc; Koekemoer, Anton; Bradley, Larry [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21208 (United States); Rosati, Piero [ESO-European Southern Observatory, D-85748 Garching bei Muenchen (Germany); Grillo, Claudio; Host, Ole [Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, DK-2100 Copenhagen (Denmark); Balestra, Italo [Max-Planck-Institut fuer Extraterrestrische Physik, Giessenbachstrasse, D-85748 Garching (Germany); Zheng, Wei; Lemze, Doron [Department of Physics and Astronomy, The Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218 (United States); Broadhurst, Tom [Department of Theoretical Physics, University of the Basque Country, P.O. Box 644, E-48080 Bilbao (Spain); Moustakas, Leonidas [Jet Propulsion Laboratory, California Institute of Technology, MS 169-327, Pasadena, CA 91109 (United States); Molino, Alberto [Instituto de Astrofisica de Andalucia (CSIC), C/Camino Bajo de Huetor 24, Granada E-18008 (Spain); and others 2013-09-10 In this work, we analyze the mass distribution of MACSJ1206.2-0847, particularly focusing on the halo properties of its cluster members. The cluster appears relaxed in its X-ray emission, but has a significant amount of intracluster light that is not centrally concentrated, suggesting that galaxy-scale interactions are still ongoing despite the overall relaxed state. The cluster lenses 12 background galaxies into multiple images and one galaxy at z = 1.033 into a giant arc and its counterimage. The multiple image positions and the surface brightness (SFB) distribution of the arc, which is bent around several cluster members, are sensitive to the cluster galaxy halo properties. We model the cluster mass distribution with a Navarro-Frenk-White profile and the galaxy halos with two parameters for the mass normalization and the extent of a reference halo assuming scalings with their observed near-infrared light. We match the multiple image positions at an rms level of 0.''85 and can reconstruct the SFB distribution of the arc in several filters to a remarkable accuracy based on this cluster model. The length scale where the enclosed galaxy halo mass is best constrained is about 5 effective radii-a scale in between those accessible to dynamical and field strong-lensing mass estimates on the one hand and galaxy-galaxy weak-lensing results on the other hand. The velocity dispersion and halo size of a galaxy with m{sub 160W,AB} = 19.2 and M{sub B,Vega} = -20.7 are {sigma} = 150 km s{sup -1} and r Almost-Equal-To 26 {+-} 6 kpc, respectively, indicating that the halos of the cluster galaxies are tidally stripped. We also reconstruct the unlensed source, which is smaller by a factor of {approx}5.8 in area, demonstrating the increase in morphological information due to lensing. We conclude that this galaxy likely has star-forming spiral arms with a red (older) central component. 16. Structure and dynamics of galaxies with a low surface-brightness disc - II. Stellar populations of bulges Morelli, L; Pizzella, A; Bontà, E Dalla; Coccato, L; Méndez-Abreu, J; Cesetti, M 2012-01-01 The radial profiles of the Hb, Mg, and Fe line-strength indices are presented for a sample of eight spiral galaxies with a low surface-brightness stellar disc and a bulge. The correlations between the central values of the line-strength indices and velocity dispersion are consistent to those known for early-type galaxies and bulges of high surface-brightness galaxies. The age, metallicity, and alpha/Fe enhancement of the stellar populations in the bulge-dominated region are obtained using stellar population models with variable element abundance ratios. Almost all the sample bulges are characterized by a young stellar population, on-going star formation, and a solar alpha/Fe enhancement. Their metallicity spans from high to sub-solar values. No significant gradient in age and alpha/Fe enhancement is measured, whereas only in a few cases a negative metallicity gradient is found. These properties suggest that a pure dissipative collapse is not able to explain formation of all the sample bulges and that other ph... 17. Extremely Bright Submillimeter Galaxies beyond the Lupus-I Star-forming Region Tamura, Y.; Kawabe, R.; Shimajiri, Y.; Tsukagoshi, T.; Nakajima, Y.; Oasa, Y.; Wilner, D. J.; Chandler, C. J.; Saigo, K.; Tomida, K.; Yun, M. S.; Taniguchi, A.; Kohno, K.; Hatsukade, B.; Aretxaga, I.; Austermann, J. E.; Dickman, R.; Ezawa, H.; Goss, W. M.; Hayashi, M.; Hughes, D. H.; Hiramatsu, M.; Inutsuka, S.; Ogasawara, R.; Ohashi, N.; Oshima, T.; Scott, K. S.; Wilson, G. W. 2015-08-01 We report detections of two candidate distant submillimeter galaxies (SMGs), MM J154506.4-344318 and MM J154132.7-350320, which are discovered in the AzTEC/ASTE 1.1 mm survey toward the Lupus-I star-forming region. The two objects have 1.1 mm flux densities of 43.9 and 27.1 mJy, and have Herschel/SPIRE counterparts as well. The Submillimeter Array counterpart to the former SMG is identified at 890 μm and 1.3 mm. Photometric redshift estimates using all available data from the mid-infrared to the radio suggest that the redshifts of the two SMGs are {z}{photo}≃ 4-5 and 3, respectively. Near-infrared objects are found very close to the SMGs and they are consistent with low-z ellipticals, suggesting that the high apparent luminosities can be attributed to gravitational magnification. The cumulative number counts at {S}1.1{mm}≥slant 25 mJy, combined with the other two 1.1 mm brightest sources, are {0.70}-0.34+0.56 deg-2, which is consistent with a model prediction that accounts for flux magnification due to strong gravitational lensing. Unexpectedly, a z\\gt 3 SMG and a Galactic dense starless core (e.g., a first hydrostatic core) could be similar in the mid-infrared to millimeter spectral energy distributions and spatial structures at least at ≳ 1\\prime\\prime . This indicates that it is necessary to distinguish the two possibilities by means of broadband photometry from the optical to centimeter and spectroscopy to determine the redshift, when a compact object is identified toward Galactic star-forming regions. 18. Galaxy And Mass Assembly (GAMA): The Bright Void Galaxy Population in the Optical and Mid-IR Penny, S J; Pimbblet, K A; Cluver, M E; Croton, D J; Owers, M S; Lange, R; Alpaslan, M; Baldry, I; Bland-Hawthorn, J; Brough, S; Driver, S P; Holwerda, B W; Hopkins, A M; Jarrett, T H; Jones, D Heath; Kelvin, L S; Lara-Lopez, M A; Liske, J; Lopez-Sanchez, A R; Loveday, J; Meyer, M; Norberg, P; Robotham, A S G; Rodrigues, M 2015-01-01 We examine the properties of galaxies in the Galaxies and Mass Assembly (GAMA) survey located in voids with radii$>10~h^{-1}$Mpc. Utilising the GAMA equatorial survey, 592 void galaxies are identified out to z~0.1 brighter than$M_{r} = -18.4$, our magnitude completeness limit. Using the$W_{\\rm{H\\alpha}}$vs. [NII]/H$\\alpha$(WHAN) line strength diagnostic diagram, we classify their spectra as star forming, AGN, or dominated by old stellar populations. For objects more massive than$5\\times10^{9}$M$_{\\odot}$, we identify a sample of 26 void galaxies with old stellar populations classed as passive and retired galaxies in the WHAN diagnostic diagram, else they lack any emission lines in their spectra. When matched to WISE mid-IR photometry, these passive and retired galaxies exhibit a range of mid-IR colour, with a number of void galaxies exhibiting [4.6]-[12] colours inconsistent with completely quenched stellar populations, with a similar spread in colour seen for a randomly drawn non-void comparison samp... 19. Spiral structure of the Galaxy: a statistical analysis of the spatial distribution of bright stars and open clusters A statistical analysis of space distribution of bright stars and open clusters in the fourth quadpant of the Galaxy is performed. It is shown that, with a probability equal practically to 100%, the Saggitarius-Carina spiral feature cannot be a chance density fluctuation in an actually homogeneous distribution of stars. The geometrical parameters of this feature are estimated: the pitch angle i=6 deg,6+ and the distance from the Sun R1=1.0 kpc. It is found that there is a statistically significant age gradient across the Saggitarius-Carina spiral arm: the young objects (O, M 1-2 staps) are shifted with Cespect to the older objects (the B, A, F) to the inner edge of the arm approximately by 100 pc. This result favours the density wave nature of the spiral structure of the Galaxy 20. Spiral structure of the Galaxy: a statistical analysis of the spatial distribution of bright stars and open clusters Pavlovskaya, E.D.; Suchkov, A.A. (Moskovskij Gosudarstvennyj Univ. (USSR). Gosudarstvennyj Astronomicheskij Inst. ' ' GAISh' ' ; Rostovskij-na-Donu Gosudarstvennyj Univ. (USSR)) A statistical analysis of space distribution of bright stars and open clusters in the fourth quadrant of the Galaxy is performed. It is shown that, with a probability equal practically to 100%, the Saggitarius-Carina spiral feature cannot be a chance density fluctuation in an actually homogeneous distribution of stars. The geometrical parameters of this feature are estimated: the pitch angle i=6 deg,6+ and the distance from the Sun R/sub 1/=1.0 kpc. It is found that there is a statistically significant age gradient across the Saggitarius-Carina spiral arm: the young objects (O, M 1-2 staps) are shifted with respect to the older objects (the B, A, F) to the inner edge of the arm approximately by 100 pc. This result favours the density wave nature of the spiral structure of the Galaxy. 1. The SCUBA-2 Cosmology Legacy Survey: blank-field number counts of 450um-selected galaxies and their contribution to the cosmic infrared background Geach, J E; Coppin, K E K; Dunlop, J S; Halpern, M; Smail, Ian; van der Werf, P; Serjeant, S; Farrah, D; Roseboom, I; Targett, T; Arumugam, V; Asboth, V; Blain, A; Chrysostomou, A; Clarke, C; Ivison, R J; Jones, S L; Karim, A; Mackenzie, T; Meijerink, R; Michalowski, M J; Scott, D; Simpson, J; Swinbank, A M; Alexander, D; Almaini, O; Aretxaga, I; Best, P; Chapman, S; Clements, D L; Conselice, C; Danielson, A L R; Eales, S; Edge, A C; Gibb, A; Hughes, D; Jenness, T; Knudsen, K K; Lacey, C; Marsden, G; McMahon, R; Oliver, S; Page, M J; Peacock, J A; Rigopoulou, D; Robson, E I; Spaans, M; Stevens, J; Webb, T M A; Willott, C; Wilson, C D; Zemcov, M 2012-01-01 The first deep blank-field 450um map (1-sigma~1.3mJy) from the SCUBA-2 Cosmology Legacy Survey (S2CLS), conducted with the James Clerk Maxwell Telescope (JCMT) is presented. Our map covers 140 arcmin^2 of the COSMOS field, in the footprint of the HST CANDELS area. Using 60 submillimetre galaxies (SMGs) detected at >3.75-sigma, we evaluate the number counts of 450um-selected galaxies with flux densities S_450>5mJy. The 8-arcsec JCMT beam and high sensitivity of SCUBA-2 now make it possible to directly resolve a larger fraction of the cosmic infrared background (CIB, peaking at ~200um) into the individual galaxies responsible for its emission than has previously been possible at this wavelength. At S_450>5mJy we resolve (7.4[+/-]0.7)x10^-2 MJy/sr of the CIB at 450um (equivalent to 16[+/-]7% of the absolute brightness measured by COBE at this wavelength) into point sources. A further ~40% of the CIB can be recovered through a statistical stack of 24um emitters in this field, indicating that the majority (~60%) o... 2. Measurements of Extragalactic Background Light from the Far UV to the Far IR from Deep Ground- and Space-based Galaxy Counts Driver, Simon P.; Andrews, Stephen K.; Davies, Luke J.; Robotham, Aaron S. G.; Wright, Angus H.; Windhorst, Rogier A.; Cohen, Seth; Emig, Kim; Jansen, Rolf A.; Dunne, Loretta 2016-08-01 We combine wide and deep galaxy number-count data from the Galaxy And Mass Assembly, COSMOS/G10, Hubble Space Telescope (HST) Early Release Science, HST UVUDF, and various near-, mid-, and far-IR data sets from ESO, Spitzer, and Herschel. The combined data range from the far UV (0.15 μm) to far-IR (500 μm), and in all cases the contribution to the integrated galaxy light (IGL) of successively fainter galaxies converges. Using a simple spline fit, we derive the IGL and the extrapolated IGL in all bands. We argue that undetected low-surface-brightness galaxies and intracluster/group light are modest, and that our extrapolated-IGL measurements are an accurate representation of the extragalactic background light (EBL). Our data agree with most earlier IGL estimates and with direct measurements in the far IR, but disagree strongly with direct estimates in the optical. Close agreement between our results and recent very high-energy experiments (H.E.S.S. and MAGIC) suggests that there may be an additional foreground affecting the direct estimates. The most likely culprit could be the adopted model of zodiacal light. Finally we use a modified version of the two-component model to integrate the EBL and obtain measurements of the cosmic optical background (COB) and cosmic infrared background of {24}-4+4 nW m‑2 sr‑1 and {26}-5+5 nW m‑2 sr‑1 respectively (48%:52%). Over the next decade, upcoming space missions such as Euclid and the Wide Field Infrared Space Telescope will have the capacity to reduce the COB error to direct detection and measurement of the reionization field. 3. Herschel and SCUBA-2 imaging and spectroscopy of a bright, lensed submillimetre galaxy at z = 2.3 Ivison, R J; Swinyard, B; Smail, Ian; Pearson, C P; Rigopoulou, D; Polehampton, E; Baluteau, J -P; Barlow, M J; Blain, A W; Bock, J; Clements, D L; Coppin, K; Cooray, A; Danielson, A; Dwek, E; Edge, A C; Franceschini, A; Fulton, T; Glenn, J; Griffin, M; Isaak, K; Leeks, S; Lim, T; Naylor, D; Oliver, S J; Page, M J; Perez-Fournon, I; Rowan-Robinson, M; Savini, G; Scott, D; Spencer, L; Valtchanov, I; Vigroux, L; Wright, G S 2010-01-01 We present a detailed analysis of the far-IR properties of the bright, lensed, z = 2.3, SMG, SMM J2135-0102, using new observations with Herschel, SCUBA-2 and the VLA. These data allow us to constrain the galaxy's SED and show that it has an intrinsic rest-frame 8-1000um luminosity, L(bol), of (2.3 +/- 0.2) x 10^12 L(sun) and a likely SFR of ~400 M(sun)/yr. The galaxy sits on the far-IR/radio correlation for far-IR-selected galaxies. At ~>70um, the SED can be described adequately by dust components with T(d) ~ 30 and 60K. Using SPIRE's Fourier Transform Spectrometer we report a detection of the [CII] 158um cooling line. If the [CII], CO and far-IR continuum arise in photo-dissociation regions, we derive a characteristic gas density, n ~ 10^3 cm^-3, and a far-UV radiation field, G_0, 10^3x stronger than the Milky Way. L([CII])/L(bol) is significantly higher than in local ULIRGs but similar to the values found in local star-forming galaxies and starburst nuclei. This is consistent with SMM J2135-0102 being powe... 4. The behaviour of dark matter associated with 4 bright cluster galaxies in the 10kpc core of Abell 3827 Massey, Richard; Smit, Renske; Swinbank, Mark; Kitching, Thomas; Harvey, David; Jauzac, Mathilde; Israel, Holger; Clowe, Douglas; Edge, Alastair; Hilton, Matt; Jullo, Eric; Leonard, Adrienne; Liesenborgs, Jori; Merten, Julian; Mohammed, Irshad; Nagai, Daisuke; Richard, Johan; Robertson, Andrew; Saha, Prasenjit; Santana, Rebecca; Stott, John; Tittley, Eric 2015-01-01 Galaxy cluster Abell 3827 hosts the stellar remnants of four almost equally bright elliptical galaxies within a core of radius 10kpc. Such corrugation of the stellar distribution is very rare, and suggests recent formation by several simultaneous mergers. We map the distribution of associated dark matter, using new Hubble Space Telescope imaging and VLT/MUSE integral field spectroscopy of a gravitationally lensed system threaded through the cluster core. We find that each of the central galaxies retains a dark matter halo, but that (at least) one of these is spatially offset from its stars. The best-constrained offset is 1.62+/-0.48kpc, where the 68% confidence limit includes both statistical error and systematic biases in mass modelling. Such offsets are not seen in field galaxies, but are predicted during the long infall to a cluster, if dark matter self-interactions generate an extra drag force. With such a small physical separation, it is difficult to definitively rule out astrophysical effects operating ... 5. PROBING THE IGM/GALAXY CONNECTION. IV. THE LCO/WFCCD GALAXY SURVEY OF 20 FIELDS SURROUNDING UV-BRIGHT QUASARS We publish the survey for galaxies in 20 fields containing ultraviolet bright quasars (with zem ∼ 0.1-0.5) that can be used to study the association between galaxies and absorption systems from the low-z intergalactic medium (IGM). The survey is magnitude limited (R ∼ 19.5 mag) and highly complete out to 10' from the quasar in each field. It was designed to detect dwarf galaxies (L ∼ 0.1L*) at an impact parameter ρ ∼ 1 Mpc (z = 0.1) from a quasar. The complete sample (all 20 fields) includes R-band photometry for 84,718 sources and confirmed redshifts for 2800 sources. This includes 1198 galaxies with 0.005 em - 0.01) at a median redshift of 0.18, which may associated with IGM absorption lines. All of the imaging was acquired with cameras on the Swope 40'' telescope and the spectra were obtained via slit mask observations using the WFCCD spectrograph on the Dupont 100'' telescope at Las Campanas Observatory. This paper describes the data reduction, imaging analysis, photometry, and spectral analysis of the survey. We tabulate the principal measurements for all sources in each field and provide the spectroscopic data set online. 6. The abundance properties of nearby late-type galaxies. II. The relation between abundance distributions and surface brightness profiles Pilyugin, L. S.; Grebel, E. K.; Zinchenko, I. A. [Astronomisches Rechen-Institut, Zentrum für Astronomie der Universität Heidelberg, Mönchhofstr. 12–14, D-69120 Heidelberg (Germany); Kniazev, A. Y., E-mail: pilyugin@mao.kiev.ua, E-mail: grebel@ari.uni-heidelberg.de, E-mail: zinchenko@mao.kiev.ua, E-mail: akniazev@saao.ac.za [South African Astronomical Observatory, PO Box 9, 7935 Observatory, Cape Town (South Africa) 2014-12-01 The relations between oxygen abundance and disk surface brightness (OH–SB relation) in the infrared W1 band are examined for nearby late-type galaxies. The oxygen abundances were presented in Paper I. The photometric characteristics of the disks are inferred here using photometric maps from the literature through bulge-disk decomposition. We find evidence that the OH–SB relation is not unique but depends on the galactocentric distance r (taken as a fraction of the optical radius R{sub 25}) and on the properties of a galaxy: the disk scale length h and the morphological T-type. We suggest a general, four-dimensional OH–SB relation with the values r, h, and T as parameters. The parametric OH–SB relation reproduces the observed data better than a simple, one-parameter relation; the deviations resulting when using our parametric relation are smaller by a factor of ∼1.4 than that of the simple relation. The influence of the parameters on the OH–SB relation varies with galactocentric distance. The influence of the T-type on the OH–SB relation is negligible at the centers of galaxies and increases with galactocentric distance. In contrast, the influence of the disk scale length on the OH–SB relation is at a maximum at the centers of galaxies and decreases with galactocentric distance, disappearing at the optical edges of galaxies. Two-dimensional relations can be used to reproduce the observed data at the optical edges of the disks and at the centers of the disks. The disk scale length should be used as a second parameter in the OH–SB relation at the center of the disk while the morphological T-type should be used as a second parameter in the relation at optical edge of the disk. The relations between oxygen abundance and disk surface brightness in the optical B and infrared K bands at the center of the disk and at optical edge of the disk are also considered. The general properties of the abundance–surface brightness relations are similar for the 7. Low Surface Brightness Galaxies selected from the 40% sky area of the ALFALFA HI survey.I.Sample and statistical properties Du, Wei; Lam, Man I; Zhu, Yinan; Lei, Fengjie; Zhou, Zhimin 2015-01-01 The population of Low Surface Brightness (LSB) galaxies is crucial for understanding the extremes of galaxy formation and evolution of the universe. As LSB galaxies are mostly rich in gas (HI), the alpha.40-SDSS DR7 sample is absolutely one of the best survey combinations to select a sample of them in the local Universe. Since the sky backgrounds are systematically overestimated for galaxy images by the SDSS photometric pipeline, particularly for luminous galaxies or galaxies with extended low surface brightness outskirts, in this paper, we above all estimated the sky backgrounds of SDSS images in the alpha.40-SDSS DR7 sample, using a precise method of sky subtraction. Once subtracting the sky background, we did surface photometry with the Kron elliptical aperture and fitted geometric parameters with an exponential profile model for each galaxy image. Basing on the photometric and geometric results, we further calculated the B-band central surface brightness, mu_{0}(B), for each galaxy and ultimately defined ... 8. Probing the cosmic-ray content of galaxy clusters by stacking Fermi-LAT count maps Huber, B; Eckert, D; Farnier, C; Manalaysay, A; Straumann, U; Walter, R 2013-01-01 Observation in radio have shown that galaxy clusters are giant reservoirs of cosmic rays (CR). Although a gamma-ray signal from the cluster volume is expected to arise through interactions of CR protons with the ambient plasma, a confirming observation is still missing. We search for a cumulative gamma-ray emission in direction of galaxy clusters by analysing a collection of stacked Fermi-LAT count maps. Additionally, we investigate possible systematic differences in the emission between cool-core and non-cool core cluster populations. Making use of a sample of 53 clusters selected from the HIFLUGCS catalog, we do not detect a significant signal from the stacked sample. The flux upper limit derived for the total stacked sample is at the level of a few 1e-11 ph cm-2 s-1 at 95% confidence level in the 1-300 GeV band, assuming power-law spectra with photon indices 2.0, 2.4, 2.8 and 3.2. Separate stacking of the cool core and non-cool core clusters in the sample lead to similar values of around 5e-11 ph cm-2 s-1 ... 9. How to Identify and Separate Bright Galaxy Clusters from the Low-frequency Radio Sky? Wang, Jingying; Xu, Haiguang; Gu, Junhua; An, Tao; Cui, Haijuan; Li, Jianxun; Zhang, Zhongli; Zheng, Qian; Wu, Xiang-Ping 2010-01-01 In this work we simulate the$50-200$MHz radio sky that is constrained in the field of view ($5^{\\circ}$radius) of the 21 Centimeter Array (21CMA), by carrying out Monte-Carlo simulations to model redshifted cosmological reionization signals and strong contaminating foregrounds, including emissions from our Galaxy, galaxy clusters, and extragalactic point sources. As an improvement of previous works, we consider in detail not only random variations of morphological and spectroscopic paramet... 10. The Formation of Submillimetre-Bright Galaxies from Gas Infall over a Billion Years Narayanan, Desika; Feldmann, Robert; Robitaille, Thomas; Hopkins, Philip; Thompson, Robert; Hayward, Christopher; Ball, David; Faucher-Giguere, Claude-Andre; Keres, Dusan 2015-01-01 Submillimetre-luminous galaxies at high-redshift are the most luminous, heavily star-forming galaxies in the Universe, and are characterised by prodigious emission in the far-infrared at 850 microns (S850 > 5 mJy). They reside in halos ~ 10^13Msun, have low gas fractions compared to main sequence disks at a comparable redshift, trace complex environments, and are not easily observable at optical wavelengths. Their physical origin remains unclear. Simulations have been able to form galaxies with the requisite luminosities, but have otherwise been unable to simultaneously match the stellar masses, star formation rates, gas fractions and environments. Here we report a cosmological hydrodynamic galaxy formation simulation that is able to form a submillimetre galaxy which simultaneously satisfies the broad range of observed physical constraints. We find that groups of galaxies residing in massive dark matter halos have rising star formation histories that peak at collective rates ~ 500-1000 Msun/yr at z=2-3, by wh... 11. The Millennium Galaxy Catalogue: Star counts and the Structure of the Galactic Stellar Halo Lemon, D; Liske, J; Driver, S; Horne, K; Lemon, David; Wyse, Rosemary F.G.; Liske, Jochen; Driver, Simon; Horne, Keith 2004-01-01 We derive a star catalogue generated from the images taken as part of the 37.5 sq. deg Millennium Galaxy Catalogue. These data, alone and together with colours gained from the Sloan Digital Sky Survey Early Data Release, allow the analysis of faint star counts (B(MGC) < 20) at high Galactic latitude (41 < b < 63), as a function of Galactic longitude (239 < l < 353). We focus here on the inner stellar halo, providing robust limits on the amplitude of substructure and on the large-scale flattening. In line with previous results, the thick disk, an old, intermediate-metallicity population, is clearly seen in the colour-magnitude diagram. We find that the Galactic stellar halo within ~10 kpc (the bulk of the stellar mass) is significantly flattened, with an axial ratio of (c/a) =0.56 +/- 0.01, again consistent with previous results. Our analysis using counts-in-cells, angular correlation functions and the Lee 2D statistic, confirms tidal debris from the Sagittarius dwarf but finds little evidence f... 12. 12CO, 13CO and C18O observations along the major axes of nearby bright infrared galaxies Tan, Qinghua; Zhang, Zhiyu; Xia, Xiaoyang 2011-01-01 We present simultaneous observations of CO,13CO and C18O J=1-0 emission in 11 nearby (cz<1000 km/s) bright infrared galaxies. Both 12CO and 13CO are detected in the centers of all galaxies, except for 13CO in NGC 3031. We have also detected C18O, CS J=2-1, and HCO+ J=1-0 emission in the nuclear regions of M82 and M51. These are the first systematical extragalactic detections of 12CO and its isotopes from the PMO 14m telescope. We have conducted half-beam spacing mapping of M82 over an area of 4'*2.5' and major axis mapping of NGC 3627, NGC 3628, NGC 4631, and M51. The radial distributions of 12CO and 13CO in NGC 3627, NGC 3628, and M51 can be well fitted by an exponential profile. The 12CO/13CO intensity ratio,R,decreases monotonically with galactocentric radius in all mapped sources. The average R in the center and disk of the galaxies are 9.9+/-3.0 and 5.6+/-1.9 respectively, much lower than the peculiar R(~24) found in the center of M82. The intensity ratios of 13CO/C18O, 13CO/HCO+ and 13CO/CS (either o... 13. A bright z=5.2 lensed submillimeter galaxy in the field of Abell 773: HLSJ091828.6+514223 Combes, F; Rawle, T D; Egami, E; Boone, F; Smail, I; Richard, J; Ivison, R J; Gurwell, M; Casey, C M; Omont, A; Alba, A Berciano; Dessauges-Zavadsky, M; Edge, A C; Fazio, G G; Kneib, J-P; Okabe, N; Pello, R; Perez-Gonzalez, P G; Schaerer, D; Smith, G P; Swinbank, A M; van der Werf, P 2012-01-01 During our Herschel Lensing Survey (HLS) of massive galaxy clusters, we have discovered an exceptionally bright submillimeter source, behind the z=0.22 cluster Abell 773, which appears to be a strongly lensed submillimeter galaxy (SMG) at z=5.2429. This source is unusual compared to most other lensed sources discovered by Herschel so far, both for its higher submm flux (\\sim 200mJy at 500micron) and its high redshift. The dominant lens is a foreground z=0.63 galaxy, not the cluster itself. From the continuum detected, we derive a far-infrared luminosity of LFIR= 1.1E14 /\\mu Lo, where \\mu is the magnification factor, likely \\sim 11. We report here the redshift identification through CO lines with the IRAM-30m, and the analysis of the gas excitation, based on CO(7-6), CO(6-5), CO(5-4) detected at IRAM and the CO(2-1) detected with the EVLA. All lines decompose in a wide and strong red component, and a narrower and weaker blue component, 540\\kms apart. Assuming the local ULIRG CO-to-H2 conversion ratio, the H2 m... 14. Investigating AGN Black Hole Masses and the M-$\\sigma_e$relation for Low Surface Brightness Galaxies Subramanian, Smitha; Das, Mousumi; George, Koshy; T, Sivarani; Prabhu, Tushar 2015-01-01 We present an analysis of the optical nuclear spectra from the active galactic nuclei (AGN) in a sample of low surface brightness (LSB) galaxies. Using data from the Sloan Digital Sky Survey (SDSS), we derived the virial black hole (BH) masses of 24 galaxies from their broad H$\\alpha$parameters. We find that our estimates of nuclear BH masses lie in the range$10^{5}-10^{7}~M_{\\odot}$, with a median mass of 5.62 x 10$^{6}~M_{\\odot}$. The bulge stellar velocity dispersion$\\sigma_{e}$was determined from the underlying stellar spectra. We compared our results with the existing BH mass - velocity dispersion ($M_{BH}-\\sigma_{e}$) correlations and found that the majority of our sample lie in the low BH mass regime and below the$M_{BH}-\\sigma_{e}$correlation. We analysed the effects of any systematic bias in the M$_{BH}$estimates, the effects of galaxy orientation in the measurement of$\\sigma_e$and the increase of$\\sigma_e$due to the presence of bars and found that these effects are insufficient to explain... 15. Ellipticity and twisting of the isophotes of some bright galaxies in Virgo Ellipticity and twisting of the isophotes of four lenticular and seven elliptical galaxies in the Virgo cluster are presented as a sample of a more complete photometric investigation. This work has been motivated by the increasing importance of this kind of information for the understanding of the spatial structure of E galaxies. The calibrated plate material from the Loiano 1.52 meter and Tautenburg Schmidt telescopes has been digitized with a PDS microdensitometer and analysed by means of the Interactive Numerical Mapping Package (INMP). Ellipticity and orientation profiles are presented in a graphical form together with a preliminary discussion. A correlation has been found between ellipticity and twisting in barred lenticulars which might help in the understanding of some E galaxies such as NGC 4406 and NGC 4374. Twisting has been detected in all of the seven ellipticals of the sample 16. The extraordinarily bright optical afterglow of GRB 991208 and its host galaxy Castro-Tirado, A.J.; Sokolov, V.V.; Gorosabel, J.; Ceron, J.M.C.; Greiner, J.; Wijers, R.A.M.J.; Jensen, B.L.; Hjorth, J.; Toft, Søren; Pedersen, H.; Palazzi, E.; Pian, E.; Masetti, N.; Sagar, R.N.; Mohan, V.; Pandey, A.K.; Pandey, S.B.; Dodonov, S.N.; Fatkhullin, T.A.; Afanasiev, V.L.; Komarova, V.N.; Moiseev, A.V.; Hudec, R.; Simon, V.; Vreeswijk, P.; Rol, E.; Klose, S.; Stecklum, B.; Zapatero-Osorio, M.R.; Caon, N.; Blake, C.; Wall, J.; Heinlein, D.; Henden, A.; Benetti, S.; Magazzu, A.; Ghinassi, F.; Tommasi, L.; Bremer, M.; Kouveliotou, C.; Guziy, S.; Shlyapnikov, A.; Hopp, U.; Feulner, G.; Dreizler, S.; Hartmann, D.; Boehnhardt, H.; Paredes, J.M.; Marti, J.; Xanthopoulos, E.; Kristen, H.E.; Smoker, J.; Hurley, K. 2001-01-01 Broad-band optical observations of the extraordinarily bright optical afterglow of the intense gamma-rag burst GRB 991208 started similar to2.1 days after the event and continued until 4 Apr. 2000. The flux decay constant of the optic al afterglow in the R-band is -2.30 +/- 0.07 up to similar to5... 17. Determination of the abundance of cosmic matter via the cell count moments of the galaxy distribution (1) Bel, Julien 2013-01-01 We demonstrate that accurate and precise information about the matter content of the universe can be retrieved via a simple cell count analysis of the 3D spatial distribution of galaxies. A new clustering statistic, the {\\it galaxy clustering ratio}$\\eta$, is the key in this process. This is defined as the ratio between one- and two-point second-order moments of the smoothed galaxy density distribution. The distinguishing feature of this statistic is its universality: on large cosmic scales both galaxies (in redshift space) and mass (in real space) display the same$\\eta$amplitude. This quantity, in addition, does not evolve as a function of redshift. As a consequence, the$\\eta$statistic provides insight into characteristic parameters of the real-space power spectrum of mass density fluctuations without the need to specify the galaxy biasing function, a model for galaxy redshift distortions nor the growing mode of density ripples. We demonstrate the method with the luminous red galaxy (LRG) sample extract... 18. GALAXYCOUNT: a JAVA calculator of galaxy counts and variances in multiband wide-field surveys to 28 AB mag Ellis, S. C.; Bland-Hawthorn, J. 2007-05-01 We provide a consistent framework for estimating galaxy counts and variances in wide-field images for a range of photometric bands. The variances include both Poissonian noise and variations due to large-scale structure. We demonstrate that our statistical theory is consistent with the counts in the deepest multiband surveys available. The statistical estimates depend on several observational parameters (e.g. seeing, signal-to-noise ratio), and include a sophisticated treatment of detection completeness. The JAVA calculator is freely available1 and offers the user the option to adopt our consistent framework or a different scheme. We also provide a summary table of statistical measures in the different bands for a range of different fields of view. Reliable estimation of the background counts has profound consequences in many areas of observational astronomy. We provide two such examples. One is from a recent study of the Sculptor galaxy NGC300 where stellar photometry has been used to demonstrate that the outer disc extends to 10 effective radii, far beyond what was thought possible for a normal low-luminosity spiral. We confirm this finding by a re-analysis of the background counts. Secondly, we determine the luminosity function of the galaxy cluster Abell 2734, both through spectroscopically determined cluster membership, and through statistical subtraction of the background galaxies using the calculator and offset fields. We demonstrate very good agreement, suggesting that expensive spectroscopic follow-up, or off-source observations, may often be bypassed via determination of the galaxy background with GALAXYCOUNT. 19. Star formation in infrared bright and infrared faint starburst interacting galaxies Lamb, Susan A.; Bushouse, Howard A.; Towns, John W. 1990-01-01 Short wavelength IUE spectra of Arp 248b and UGC 8315N are combined with optical spectra and interpreted using a combination of spectrum synthesis and spectral diagnostics to place constraints on the massive star populations of the central regions of these galaxies and to deduce information about the star formation histories in the last 10(exp 8) years. The authors find that both galaxies have substantial fractions of their optical light coming from massive stars and that Arp 248b may be dominated in the UV by WR stars. The UV spectra are dominated by radiation from evolved massive stars and the authors place and age on the burst in Arp 248b of a few tens of millions of years. 20. SERENDIPITOUS ALMA DETECTION OF A DISTANT CO-EMITTING X-RAY BRIGHT GALAXY Tamura, Yoichi [Institute of Astronomy, The University of Tokyo, Mitaka, Tokyo 181-0015 (Japan); Saito, Toshiki; Iono, Daisuke; Kawabe, Ryohei [National Astronomical Observatory of Japan, Mitaka, Tokyo 181-8588 (Japan); Tsuru, Takeshi G.; Uchida, Hiroyuki [Division of Physics and Astronomy, Kyoto University, Kitashirakawa-Oiwake-Cho, Sakyo, Kyoto 606-8502 (Japan); Yun, Min S. [Department of Astronomy, University of Massachusetts, 710 North Pleasant Street, Amherst, MA 01003 (United States); Espada, Daniel, E-mail: ytamura@ioa.s.u-tokyo.ac.jp [Joint ALMA Observatory, Alonso de Cordova 3107, Vitacura, Santiago 763 0355 (Chile) 2014-02-01 We report the detection of a distant star-forming galaxy, ALMA J010748.3–173028, which is identified by a 13σ emission line at 99.75 GHz (SΔv = 3.1 Jy km s{sup –1}), behind the nearby merging galaxies VV114 using the Atacama Large Millimeter/submillimeter Array (ALMA) Band 3. We also find an 880 μm counterpart with ALMA Band 7 (S {sub 880μm} = 11.2 mJy). A careful comparison of the intensities of the line and the continuum suggests that the line is a redshifted {sup 12}CO transition. A photometric redshift analysis using the infrared to radio data favors a CO redshift of z = 2.467, although z = 3.622 is acceptable. We also find a hard X-ray counterpart, suggesting the presence of a luminous (L {sub X} ∼ 10{sup 44} erg s{sup –1}) active galactic nucleus obscured by a large hydrogen column (N {sub H} ∼ 2 × 10{sup 23} cm{sup –2} if z = 2.47). A cosmological simulation shows that the chance detection rate of a CO-emitting galaxy at z > 1 with ≥1 Jy km s{sup –1} is ∼10{sup –3} per single ALMA field of view and 7.5 GHz bandwidth at 99.75 GHz. This demonstrates that ALMA has sufficient sensitivity to find an emission-line galaxy such as ALMA J010748.3–173028 even by chance, although the likelihood of stumbling across such a source is not high. 1. ASCA observation of three bright early-type galaxies: NGC 4472, NGC 4406, and NGC 4636 Awaki, Hisamitsu; Mushotzky, Richard; Tsuru, Takeshi; Fabian, Andrew C.; Fukazawa, Yasushi; Loewenstein, Michael; Makishima, Kazuo; Matsumoto, Hironori; Matsushita, Kyoko; Mihara, Tatehiro 1994-01-01 We report Advanced Satellite for Cosmology and Astrophysics (ASCA) 0.3-10 keV and X-ray observations of three early type galaxies, NGC 4472, NGC 4406, and NGC 4636. The extended mission in these galaxies is well described by thin thermal eimssion from hot gas. The gas temperature is 0.92 +/- 0.02 keV for NGC 4472, 0.79 +/- 0.01 keV for NGC 4406, and 0.73 +/- 0.02 keV for NGC 4636. The metal abundance for NGC 4472, NGC 4406, and NGC 4636 are, under the assumption of solar ratios, 0.63 +/- 0.15, 0.45 +/- 0.10, and 0.38 +/- 0.07, respectively. Detailed analysis has allowed determination of the abundances of oxygen, silicon, sulfur, and iron. The observed abundances are consistent with the solar ratios. For NGC 4472 and NGC 4406 we also determined the mean temperature of the gas producing the Si lines from the ratio of the Si H to He-like lines and find it to be consistent with the continuum temperature. The X-ray temperature is in good agreement with the observed optical velocity dispersion, stellar density profile, and gas density profile. Our data indicates that the supernova rate should be less than one fifth of the nominal rate in early type galaxies. We derive the mass of these systems within fixed angular scales and find that M/L greater than 40, confirming that elliptical galaxies are dark matter dominated at large radii. 2. Surface brightness profiles of blue compact dwarf galaxies in the GOODS-N and GOODS-S field Lian, Jianhui; Jiang, Ning; Yan, Wei; Gao, Yulong 2016-01-01 We investigate the structural properties of the underlying hosts of 34 blue compact dwarf (BCD) galaxies with deep near-infrared (NIR) photometry. The BCD sample is selected from the Cosmic Assembly Near-IR Deep Extragalactic Legacy Survey in the Great observatories origins Deep Survey North and South fields. We extract the surface brightness profile (SBP) in the optical F 435W and NIR F 160W bands. The SBPs of BCDs in the H band reach 26 mag arcsec^-2 at the 3\\sigma level, which is so far the deepest NIR imaging of BCDs. Then we fit the SBPs with one- and two- component Sersic models. About half of the BCDs favour the two-component model which significantly improves the fit quality. The effective radii of the underlying hosts of BCDs in the B band are smaller than those of early-type dwarfs (dEs) and dwarf irregulars at a fixed luminosity. This discrepancy is similar to findings in many previous works. However, the difference in structural parameters between BCDs and other dwarf galaxies seems to be less sig... 3. Probing Very Bright-End of Galaxy Luminosity Function at z >~ 7 Using Hubble Space Telescope Pure Parallel Observations Yan, Haojing; Zamojski, Michel A; Windhorst, Rogier A; McCarthy, Patrick J; Fan, Xiaohui; Röttgering, Huub J A; Koekemoer, Anton M; Robertson, Brant E; Davé, Romeel; Cai, Zheng 2010-01-01 We report the first results from the Hubble Infrared Pure Parallel Imaging Extragalactic Survey, which utilizes the pure parallel orbits of the Hubble Space Telescope to do deep imaging along a large number of random sightlines. To date, our analysis includes 26 widely separated fields observed by the Wide Field Camera 3, which amounts to 122.8 sq. arcmin in total area. We have found three bright Y098-dropouts, which are candidate galaxies at z >~ 7.4. One of these objects shows a peculiar indication of variability and its nature is uncertain. The other two objects are among the brightest candidate galaxies at these redshifts known to date (L>2L*). Such very luminous objects could be the progenitors of the high-mass LBGs observed at lower redshifts. While our sample is still limited in size, it is much less subject to the uncertainty caused by "cosmic variance" than other samples because it is derived using fields along many random sightlines. We find that the existence of the brightest candidate at z~7.4 is ... 4. CARMA SURVEY TOWARD INFRARED-BRIGHT NEARBY GALAXIES (STING). III. THE DEPENDENCE OF ATOMIC AND MOLECULAR GAS SURFACE DENSITIES ON GALAXY PROPERTIES Wong, Tony; Xue, Rui [Department of Astronomy, University of Illinois, Urbana, IL 61801 (United States); Bolatto, Alberto D.; Fisher, David B.; Vogel, Stuart N. [Department of Astronomy, University of Maryland, College Park, MD 20742 (United States); Leroy, Adam K. [National Radio Astronomy Observatory, Charlottesville, VA 22903 (United States); Blitz, Leo [Department of Astronomy, University of California, Berkeley, CA 94720 (United States); Rosolowsky, Erik [Department of Physics, University of Alberta, Edmonton, AB T6G 2E1 (Canada); Bigiel, Frank [Institut für theoretische Astrophysik, Zentrum für Astronomie der Universität Heidelberg, Albert-Ueberle Str. 2, D-69120 Heidelberg (Germany); Ott, Jürgen [National Radio Astronomy Observatory, Socorro, NM 87801 (United States); Rahman, Nurur [Department of Physics, C1 Lab 140, University of Johannesburg, P.O. Box 524, Auckland Park, Johannesburg 2006 (South Africa); Walter, Fabian [Max-Planck-Institut für Astronomie, Konigstuhl 17, D-69117 Heidelberg (Germany) 2013-11-01 We investigate the correlation between CO and H I emission in 18 nearby galaxies from the CARMA Survey Toward IR-Bright Nearby Galaxies (STING) at sub-kpc and kpc scales. Our sample, spanning a wide range in stellar mass and metallicity, reveals evidence for a metallicity dependence of the H I column density measured in regions exhibiting CO emission. Such a dependence is predicted by the equilibrium model of McKee and Krumholz, which balances H{sub 2} formation and dissociation. The observed H I column density is often smaller than predicted by the model, an effect we attribute to unresolved clumping, although values close to the model prediction are also seen. We do not observe H I column densities much larger than predicted, as might be expected were there a diffuse H I component that did not contribute to H{sub 2} shielding. We also find that the H{sub 2} column density inferred from CO correlates strongly with the stellar surface density, suggesting that the local supply of molecular gas is tightly regulated by the stellar disk. 5. CARMA SURVEY TOWARD INFRARED-BRIGHT NEARBY GALAXIES (STING). III. THE DEPENDENCE OF ATOMIC AND MOLECULAR GAS SURFACE DENSITIES ON GALAXY PROPERTIES We investigate the correlation between CO and H I emission in 18 nearby galaxies from the CARMA Survey Toward IR-Bright Nearby Galaxies (STING) at sub-kpc and kpc scales. Our sample, spanning a wide range in stellar mass and metallicity, reveals evidence for a metallicity dependence of the H I column density measured in regions exhibiting CO emission. Such a dependence is predicted by the equilibrium model of McKee and Krumholz, which balances H2 formation and dissociation. The observed H I column density is often smaller than predicted by the model, an effect we attribute to unresolved clumping, although values close to the model prediction are also seen. We do not observe H I column densities much larger than predicted, as might be expected were there a diffuse H I component that did not contribute to H2 shielding. We also find that the H2 column density inferred from CO correlates strongly with the stellar surface density, suggesting that the local supply of molecular gas is tightly regulated by the stellar disk 6. Hubble space telescope observations of the afterglow, supernova, and host galaxy associated with the extremely bright GRB 130427A Levan, A. J. [Department of Physics, University of Warwick, Coventry, CV4 7AL (United Kingdom); Tanvir, N. R.; Wiersema, K. [Department of Physics and Astronomy, University of Leicester, University Road, Leicester, LE1 7RH (United Kingdom); Fruchter, A. S.; Hounsell, R. A.; Graham, J. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Hjorth, J.; Fynbo, J. P. U. [Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, DK-2100 Copenhagen (Denmark); Pian, E. [INAF, Trieste Astronomical Observatory, via G.B. Tiepolo 11, I-34143 Trieste (Italy); Mazzali, P. [Astrophysics Research Institute, Liverpool John Moores University, IC2 Liverpool Science Park 146 Brownlow Hill, Liverpool L3 5RF (United Kingdom); Perley, D. A. [Department of Astronomy, California Institute of Technology, MC 249-17, 1200 East California Blvd., Pasadena, CA 91125 (United States); Cano, Z. [Centre for Astrophysics and Cosmology, Science Institute, University of Iceland, Dunhagi 5, 107 Reykjavik (Iceland); Cenko, S. B. [Astrophysics Science Division, NASA Goddard Space Flight Center, Mail Code 661, Greenbelt, MD 20771 (United States); Kouveliotou, C. [Science and Technology Office, ZP12, NASA/Marshall Space Flight Center, Huntsville, AL 35812 (United States); Pe' er, A. [Department of Physics, University College Cork, Cork (Ireland); Misra, K., E-mail: a.j.levan@warwick.ac.uk [Aryabhatta Research Institute of Observational Sciences, Manora Peak, Nainital-263 002 (India) 2014-09-10 We present Hubble Space Telescope (HST) observations of the exceptionally bright and luminous Swift gamma-ray burst (GRB), GRB 130427A. At z = 0.34, this burst affords an excellent opportunity to study the supernova (SN) and host galaxy associated with an intrinsically extremely luminous burst (E {sub iso} > 10{sup 54} erg): more luminous than any previous GRB with a spectroscopically associated SN. We use the combination of the image quality, UV capability, and invariant point-spread function of HST to provide the best possible separation of the afterglow, host, and SN contributions to the observed light ∼17 rest-frame days after the burst, utilizing a host subtraction spectrum obtained one year later. Advanced Camera for Surveys grism observations show that the associated SN, SN 2013cq, has an overall spectral shape and luminosity similar to SN 1998bw (with a photospheric velocity, v {sub ph} ∼ 15, 000 km s{sup –1}). The positions of the bluer features are better matched by the higher velocity SN 2010bh (v {sub ph} ∼ 30, 000 km s{sup –1}), but this SN is significantly fainter and fails to reproduce the overall spectral shape, perhaps indicative of velocity structure in the ejecta. We find that the burst originated ∼4 kpc from the nucleus of a moderately star forming (1 M {sub ☉} yr{sup –1}), possibly interacting disk galaxy. The absolute magnitude, physical size, and morphology of this galaxy, as well as the location of the GRB within it, are also strikingly similar to those of GRB 980425/SN 1998bw. The similarity of the SNe and environment from both the most luminous and least luminous GRBs suggests that broadly similar progenitor stars can create GRBs across six orders of magnitude in isotropic energy. 7. Hubble space telescope observations of the afterglow, supernova, and host galaxy associated with the extremely bright GRB 130427A We present Hubble Space Telescope (HST) observations of the exceptionally bright and luminous Swift gamma-ray burst (GRB), GRB 130427A. At z = 0.34, this burst affords an excellent opportunity to study the supernova (SN) and host galaxy associated with an intrinsically extremely luminous burst (E iso > 1054 erg): more luminous than any previous GRB with a spectroscopically associated SN. We use the combination of the image quality, UV capability, and invariant point-spread function of HST to provide the best possible separation of the afterglow, host, and SN contributions to the observed light ∼17 rest-frame days after the burst, utilizing a host subtraction spectrum obtained one year later. Advanced Camera for Surveys grism observations show that the associated SN, SN 2013cq, has an overall spectral shape and luminosity similar to SN 1998bw (with a photospheric velocity, v ph ∼ 15, 000 km s–1). The positions of the bluer features are better matched by the higher velocity SN 2010bh (v ph ∼ 30, 000 km s–1), but this SN is significantly fainter and fails to reproduce the overall spectral shape, perhaps indicative of velocity structure in the ejecta. We find that the burst originated ∼4 kpc from the nucleus of a moderately star forming (1 M ☉ yr–1), possibly interacting disk galaxy. The absolute magnitude, physical size, and morphology of this galaxy, as well as the location of the GRB within it, are also strikingly similar to those of GRB 980425/SN 1998bw. The similarity of the SNe and environment from both the most luminous and least luminous GRBs suggests that broadly similar progenitor stars can create GRBs across six orders of magnitude in isotropic energy. 8. Hubble Space Telescope Observations of the Afterglow, Supernova and Host Galaxy Associated with the Extremely Bright GRB 130427A Levan, A.J.; Tanvir, N. R.; Fruchter, A. S.; Hjorth, J.; Pian, E.; Mazzali, P.; Hounsell, R. A.; Perley, D. A.; Cano, Z.; Graham, J.; Cenko, S. B.; Fynbo, J. P. U.; Kouveliotou, C.; Pe'er, A.; Misra, K.; Wiersema, K. 2014-01-01 We present Hubble Space Telescope (HST) observations of the exceptionally bright and luminous Swift gamma-ray burst, GRB 130427A. At z=0.34 this burst affords an excellent opportunity to study the supernova and host galaxy associated with an intrinsically extremely luminous burst (E(sub iso) greater than 10(exp 54) erg): more luminous than any previous GRB with a spectroscopically associated supernova. We use the combination of the image quality, UV capability and and invariant PSF of HST to provide the best possible separation of the afterglow, host and supernova contributions to the observed light approximately 17 rest-frame days after the burst utilising a host subtraction spectrum obtained 1 year later. Advanced Camera for Surveys (ACS) grism observations show that the associated supernova, SN 2013cq, has an overall spectral shape and luminosity similar to SN 1998bw (with a photospheric velocity, vph approximately 15,000 kilometers per second). The positions of the bluer features are better matched by the higher velocity SN 2010bh (vph approximately 30,000 kilometers per second), but SN 2010bh (vph approximately 30,000 kilometers per second but this SN is significantly fainter, and fails to reproduce the overall spectral shape, perhaps indicative of velocity structure in the ejecta. We find that the burst originated approximately 4 kpc from the nucleus of a moderately star forming (1 Solar Mass yr(exp-1)), possibly interacting disc galaxy. The absolute magnitude, physical size and morphology of this galaxy, as well as the location of the GRB within it are also strikingly similar to those of GRB980425SN 1998bw. The similarity of supernovae and environment from both the most luminous and least luminous GRBs suggests broadly similar progenitor stars can create GRBs across six orders of magnitude in isotropic energy. 9. Discovery of megaparsec-scale, low surface brightness nonthermal emission in merging galaxy clusters using the green bank telescope We present results from a study of 12 X-ray bright clusters at 1.4 GHz with the 100 m Green Bank Telescope. After subtraction of point sources using existing interferometer data, we reach a median (best) 1σ rms sensitivity level of 0.01 (0.006) μJy arcsec–2, and find a significant excess of diffuse, low surface brightness emission in 11 of 12 Abell clusters observed. We also present initial results at 1.4 GHz of A2319 from the Very Large Array. In particular, we find: (1) four new detections of diffuse structures tentatively classified as two halos (A2065, A2069) and two relics (A2067, A2073); (2) the first detection of the radio halo in A2061 at 1.4 GHz, which qualifies this as a possible ultra-steep spectrum halo source with a synchrotron spectral index of α ∼ 1.8 between 327 MHz and 1.4 GHz; (3) a ∼2 Mpc radio halo in the sloshing, minor-merger cluster A2142; (4) a >2× increase of the giant radio halo extent and luminosity in the merging cluster A2319; (5) a ∼7× increase to the integrated radio flux and >4× increase to the observed extent of the peripheral radio relic in A1367 to ∼600 kpc, which we also observe to be polarized on a similar scale; (6) significant excess emission of ambiguous nature in three clusters with embedded tailed radio galaxies (A119, A400, A3744). Our radio halo detections agree with the well-known X-ray/radio luminosity correlation, but they are larger and fainter than current radio power correlation studies would predict. The corresponding volume-averaged synchrotron emissivities are 1-2 orders of magnitude below the characteristic value found in previous studies. Some of the halo-like detections may be some type of previously unseen, low surface brightness radio halo or blend of unresolved shock structures and sub-Mpc-scale turbulent regions associated with their respective cluster merging activity. Four of the five tentative halos contain one or more X-ray cold fronts, suggesting a possible connection between gas 10. Morphological Number Counts of Galaxies in the Hubble Deep Field South Lee, Myung Gyoon; Hwang, Narae 2000-01-01 We present a study of photometric properties of the galaxies in the Hubble Deep Field South (HDFS) based on the released WFPC2 images obtained with the Hubble Space Telescope (HST). We have classified about 340 galaxies with$I

11. The Detection of a Population of Submillimeter-Bright, Strongly-Lensed Galaxies

Negrello, Mattia; De Zotti, G; Cooray, A; Verma, A; Bock, J; Frayer, D T; Gurwell, M A; Omont, A; Neri, R; Dannerbauer, H; Leeuw, L L; Barton, E; Cooke, J; Kim, S; da Cunha, E; Rodighiero, G; Cox, P; Bonfield, D G; Jarvis, M J; Serjeant, S; Ivison, R J; Dye, S; Aretxaga, I; Hughes, D H; Ibar, E; Bertoldi, F; Valtchanov, I; Eales, S; Dunne, L; Driver, S P; Auld, R; Buttiglione, S; Cava, A; Grady, C A; Clements, D L; Dariush, A; Fritz, J; Hill, D; Hornbeck, J B; Kelvin, L; Lagache, G; Lopez-Caniego, M; Gonzalez-Nuevo, J; Maddox, S; Pascale, E; Pohlen, M; Rigby, E E; Robotham, A; Simpson, C; Smith, D J B; Temi, P; Thompson, M A; Woodgate, B E; York, D G; Aguirre, J E; Beelen, A; Blain, A; Baker, A J; Birkinshaw, M; Blundell, R; Bradford, C M; Burgarella, D; Danese, L; Dunlop, J S; Fleuren, S; Glenn, J; Harris, A I; Kamenetzky, J; Lupu, R E; Maddalena, R J; Madore, B F; Maloney, P R; Matsuhara, H; Michalowski, M J; Murphy, E J; Naylor, B J; Nguyen, H; Popescu, C; Rawlings, S; Rigopoulou, D; Scott, D; Scott, K S; Seibert, M; Smail, I; Tuffs, R J; Vieira, J D; van der Werf, P P; Zmuidzinas, J; 10.1126/science.1193420

2010-01-01

Gravitational lensing is a powerful astrophysical and cosmological probe and is particularly valuable at submillimeter wavelengths for the study of the statistical and individual properties of dusty starforming galaxies. However the identification of gravitational lenses is often time-intensive, involving the sifting of large volumes of imaging or spectroscopic data to find few candidates. We used early data from the Herschel Astrophysical Terahertz Large Area Survey to demonstrate that wide-area submillimeter surveys can simply and easily detect strong gravitational lensing events, with close to 100% efficiency.

12. Low Surface Brightness Galaxies Selected from the 40% Sky Area of the ALFALFA H I Survey. I. Sample and Statistical Properties

Du, Wei; Wu, Hong; Lam, Man I.; Zhu, Yinan; Lei, Fengjie; Zhou, Zhimin

2015-06-01

The population of low surface brightness (LSB) galaxies, which are objects with central surface brightnesses at least one magnitude fainter than the night sky, is crucial for understanding the extremes of galactic formation and evolution of the universe. As LSB galaxies are mostly rich in gas (H i), the α.40 Sloan Digital Sky Survey (SDSS) Data Release 7 (DR7) sample is one of the best survey combinations to select a sample of them in the local universe. Since the sky backgrounds are systematically overestimated for galactic images by the SDSS photometric pipeline, particularly for luminous galaxies or galaxies with extended LSB outskirts, in this paper, we above all estimated the sky backgrounds of SDSS images accurately in both the g and r bands for each galaxy in the α.40 SDSS DR7 sample, using a precise method of sky subtraction. Once subtracting the sky background, we did surface photometry with the Kron elliptical aperture using the SExtractor software and fitted geometric parameters with an exponential profile model using the Galfit software for each galactic image in the α.40 SDSS DR7 sample. Based on the photometric and geometric results, we further calculated the B-band central surface brightness, {{μ }0}(B), for each galaxy and ultimately defined a sample of LSB galaxies consisting of 1129 galaxies with {{μ }0}(B) > 22.5 mag arcsec‑2 and the axis ratio b/a > 0.3 from the 12,423 α.40 SDSS DR7 galaxies. This H i-selected sample of LSB galaxies is a relatively unbiased sample of gas-rich and disk-dominated LSB galaxies, which is complete both in H i observation and the optical magnitude within the limit of the SDSS DR7 photometric survey. This LSB galactic sample spans from 22.5 to 28.3 in {{μ }0}(B) with a fraction of 4% fainter than 25.0 mag arcsec‑2 in B-band central surface brightness and distributes from ‑27.0 to ‑12.3 mag in absolute magnitude in the B band (M(B)), including the 43 faintest galaxies (M(B) > ‑17.3 mag). This sample is

13. Digitized POSS-II: Galaxy Number Counts in Two Colors Over a Multi-Plate Region

Weir, N.; Djorgovski, S.; Fayyad, U.

1993-05-01

We have developed a software system for the reduction and analysis of the Palomar-STScI Digital Sky Survey (cf. B.A.A.S. 23, p. 1434, and B.A.A.S. 24, pp. 741, 750, and 1139). This system, named SKICAT, uses a number of image processing and machine-learning based modules, and conducts pipeline processing of the plate scans, from raw pixel measurement, object classification, photometric matching of multiple plate images, to high-level catalog database manipulation using an X-windows based GUI. We are now in the process of implementing a variety of tools for the scientific and multivariate statistical analysis of the object catalogs. We will present our initial results on galaxy and star counts in two colors (photographic J and F, calibrated to Gunn g and r bands), for a multi-plate region near the north Galactic pole, covering up to 5 Survey fields ( ~ 125 square degrees), and up to 11 Survey fields ( ~ 275 square degrees) in a single color. The data have been uniformly calibrated using CCD sequences and plate overlaps over the range 16 models. Acknowledgements: The POSS-II is partially funded by grants to Caltech from the Eastman Kodak Co., the National Geographic Society, the Samuel Oschin Foundation, the NSF grants AST 84-08225 and AST 87-19465, and the NASA grants NGL 05002140 and NAGW 1710. NW was supported in part by a NSF graduate fellowship and by IPAC. SD acknowledges a partial support from the NASA contract NAS5-31348, the NSF PYI award AST-9157412, the Caltech President's fund, and JPL. Work at JPL is performed under a contract with the NASA.

14. Probing the evolution of early-type galaxies using multi-colour number counts and redshift distributions

Nakata, F; Doi, M; Kashikawa, N; Kawasaki, W; Komiyama, Yu; Okamura, S; Sekiguchi, M; Yagi, M; Yasuda, N; Nakata, Fumiaki; Shimasaku, Kazuhiro; Doi, Mamoru; Kashikawa, Nobunari; Kawasaki, Wataru; Komiyama, Yutaka; Okamura, Sadanori; Sekiguchi, Maki; Yagi, Masafumi; Yasuda, Naoki

1999-01-01

We investigate pure luminosity evolution models for early-type (elliptical and S0) galaxies (i.e., no number density change or morphology transition), and examine whether these models are consistent with observed number counts in the B, I and K bands and redshift distributions of two samples of faint galaxies selected in the I and K bands. The models are characterized by the star formation time scale $\\tau_{SF}$ and the time $t_{gw}$ when galactic wind blows in addition to several other conventional parameters. We find the single-burst model ($\\tau_{SF}$=0.1 Gyr and $t_{gw}$=0.353 Gyr), which is known to reproduce the photometric properties of early-type galaxies in clusters, is inconsistent with redshift distributions of early-type galaxies in the field environment due to overpredictions of galaxies at $z\\gsim1.4$ even with strong extinction which is at work until $t_{gw}$. In order for dust extinction to be more effective, we change $\\tau_{SF}$ and $t_{gw}$ as free parameters, and find that models with $\\ta... 15. Visibility of galaxies It is stated that counts of galaxies could be seriously biased by selection effects, largely influenced by the brightness of the night sky. To illustrate this suppose the Earth were situated near the center of a giant elliptical galaxy. The mean surface brightness of the sky would then appear some 8 to 9 mag. brighter than is observed from our position in the Galaxy. Extragalactic space would then appear to be empty void; spiral and irregular galaxies would be invisible, and all that could be easily detected would be the core regions of galaxy ellipticals very similar to our own. Much of the Universe would be blinded by the surface brightness of the parent galaxy. This blinding, however, is a relative matter and the question arises as to what extent we are blinded by the spiral galaxy in which we exist. Strong indirect evidence exists that our knowledge of galaxies is heavily biased by the sky background, and the true population of extragalactic space may be very different from that seen. Other relevant work is also discussed, and further investigational work is indicated. (U.K.) 16. Morphological Number Counts and Redshift Distributions to I = 25 from the Hubble Deep Fields: Constraints on Cosmological Models from Early Type Galaxies Phillipps, S.; Driver, S. P.; Couch, W. J.; Fernandez-Soto, A.; Bristow, P. D.; Odewahn, S. C.; Windhorst, R. A.; Lanzetta, K. 2000-01-01 We combine magnitude and photometric redshift data on galaxies in the Hubble Deep Fields with morphological classifications in order to separate out the distributions for early type galaxies. The updated morphological galaxy number counts down to I = 25 and the corresponding redshift distributions are used as joint constraints on cosmological models, in particular on the values of the density parameter Omega_{0} and normalised cosmological constant Lambda_{0}. We find that an Einstein - de Si... 17. SPECTROPOLARIMETRY WITH THE ALLEN TELESCOPE ARRAY: FARADAY ROTATION TOWARD BRIGHT POLARIZED RADIO GALAXIES We have observed 37 bright, polarized radio sources with the Allen Telescope Array (ATA) to present a novel analysis of their Faraday rotation properties. Each source was observed during the commissioning phase with two to four 100 MHz bands at frequencies ranging from 1 to 2 GHz. These observations demonstrate how the continuous frequency coverage of the ATA's log-periodic receiver can be applied to the study of Faraday rotation measures (RMs). We use RM synthesis to show that wide-bandwidth data can find multiple RM components toward a single source. Roughly a quarter of the sources studied have extra RM components with high confidence (brighter than ∼40 mJy), when observing with an RM resolution of roughly 100 rad m-2. These extra components contribute 10%-70% of the total polarized flux. This is the first time multiple RM components have been identified in a large sample of point sources. For our observing configuration, these extra RM components bias the measurement of the peak RM by 10-15 rad m-2; more generally, the peak RM cannot be determined more precisely than the RM beam size. Comparing our 1-2 GHz RM spectra to Very Long Baseline Array (VLBA) polarimetric maps shows that both techniques can identify complicated Faraday structures in the sources. However, the RM values and fractional polarization are generally smaller at lower frequencies than in the higher frequency VLBA maps. With a few exceptions, the RMs from this work are consistent with that of earlier, narrow-bandwidth, all-sky surveys. This work also describes the polarimetry calibration procedure and that on-axis ATA observations of linear polarization can be calibrated to an accuracy of 0.2% of Stokes I. Future research directions include studying the time-dependent RM structure in active galactic nuclei and enabling accurate, wide-area RM surveys to test models of Galactic and extragalactic magnetic fields. 18. Hubble Space Telescope observations of the afterglow, supernova and host galaxy associated with the extremely bright GRB 130427A Levan, A J; Fruchter, A S; Hjorth, J; Pian, E; Mazzali, P; Perley, D A; Cano, Z; Graham, J; Hounsell, R A; Cenko, S B; Fynbo, J P U; Kouveliotou, C; Pe'er, A; Misra, K; Wiersema, K 2013-01-01 We present Hubble Space Telescope observations of the exceptionally bright and luminous Swift gamma-ray burst, GRB 130427A. At z=0.34 this burst affords an excellent opportunity to study the supernova associated with an intrinsically extremely luminous burst (E_iso >10^54 erg), much more luminous than almost all previous GRBs with spectroscopically associated supernovae. We use the combination of the image quality and UV capability of HST to provide the best possible separation of the afterglow, host and supernova contributions to the observed light ~17 rest-frame days after the burst. We find that the burst originated ~4 kpc from the nucleus of a moderately star forming (1 Msol/yr), possibly interacting disc galaxy. ACS grism observations show that the associated supernova, SN 2013cq, is well fit in the red by an SN 1998bw-like supernovae of similar luminosity and velocity (v~15,000 km/s). The positions of the bluer features are better matched by the higher velocity SN 2010bh (v~30,000 km/s), but this SN fai... 19. An ultra-bright, dust-obscured, millimeter-galaxy beyond the Bullet Cluster (1E0657-56) Wilson, G W; Hughes, D; Ezawa, H; Austermann, J E; Doyle, S; Hernandez-Curiel, I; Kawabe, R; Kitayama, T; Kohno, K; Kuboi, A; Matsuo, H; Mauskopf, P D; Murakoshi, Y; Montana, A; Natarajan, P; Oshima, T; Ota, N; Perera, T; Rand, J; Scott, K S; Tanaka, K; Tsuboi, M; Williams, C C; Yun, M S 2008-01-01 Deep 1.1 mm continuum observations of the interacting galaxy-clusters 1E0657-56 (the Bullet Cluster) taken with the millimeter-wavelength camera AzTEC on the 10-m Atacama Submillimeter Telescope Experiment (ASTE), have revealed an extremely bright (S_1.1mm=15.9mJy) unresolved source. This source, MMJ065837-5557.0, lies close to a maximum in the density of underlying mass-distribution as traced by the weak-lensing analysis of Clowe et al. 2006, towards the larger of the two interacting clusters. A lensing-derived mass model for the Bullet Cluster shows a critical-line (caustic) of magnification very near the AzTEC source, likely providing a high boost (> 20) to its millimeter flux. We explore various scenarios to explain the colors, morphologies and positional offsets between the potential optical and IR counterparts, and their relationship with MMJ065837-5557.0. One interpretation is that MMJ065837-5557.0 is an individual distant LIRG, with multiple HST and Spitzer images due to the strong lensing by the Bull... 20. Galaxies in X-ray Selected Clusters and Groups in Dark Energy Survey Data: Stellar Mass Growth of Bright Central Galaxies Since z~1.2 Zhang, Y; Mckay, T; Rooney, P; Evrard, A E; Romer, A K; Perfecto, R; Song, J; Desai, S; Mohr, J; Wilcox, H; Bermeo, A; Jeltema, T; Hollowood, D; Bacon, D; Capozzi, D; Collins, C; Das, R; Gerdes, D; Hennig, C; Hilton, M; Hoyle, B; Kay, S; Liddle, A; Mann, R G; Mehrtens, N; Nichol, R C; Papovich, C; Sahlén, M; Soares-Santos, M; Stott, J; Viana, P T; Abbott, T; Abdalla, F B; Banerji, M; Bauer, A H; Benoit-Lévy, A; Bertin, E; Brooks, D; Buckley-Geer, E; Burke, D L; Rosell, A Carnero; Castander, F J; Diehl, H T; Doel, P; Cunha, C E; Eifler, T F; Neto, A Fausti; Fernandez, E; Flaugher, B; Fosalba, P; Frieman, J; Gaztanaga, E; Gruen, D; Gruendl, R A; Honscheid, K; James, D; Kuehn, K; Kuropatkin, N; Lahav, O; Maia, M A G; Makler, M; Marshall, J L; Martini, Paul; Miquel, R; Ogando, R; Plazas, A A; Roodman, A; Rykoff, E S; Sako, M; Sanchez, E; Scarpine, V; Schubnell, M; Sevilla, I; Smith, R C; Sobreira, F; Suchyta, E; Swanson, M E C; Tarle, G; Thaler, J; Tucker, D; Vikram, V; Da Costa, L N 2015-01-01 Using the science verification data of the Dark Energy Survey (DES) for a new sample of 106 X-Ray selected clusters and groups, we study the stellar mass growth of Bright Central Galaxies (BCGs) since redshift 1.2. Compared with the expectation in a semi-analytical model applied to the Millennium Simulation, the observed BCGs become under-massive/under-luminous with decreasing redshift. We incorporate the uncertainties associated with cluster mass, redshift, and BCG stellar mass measurements into analysis of a redshift-dependent BCG-cluster mass relation,$m_{*}\\propto(\\frac{M_{200}}{1.5\\times 10^{14}M_{\\odot}})^{0.24\\pm 0.08}(1+z)^{-0.19\\pm0.34}$, and compare the observed relation to the simulation prediction. We estimate the average growth rate since z = 1.0 for BCGs hosted by clusters of$M_{200, z}=10^{13.8}M_{\\odot}$, at$z=1.0$:$m_{*, BCG}$appears to have grown by$0.13\\pm0.11$dex, in tension at$\\sim 2.5 \\sigma$significance level with the 0.4 dex growth rate expected in the simulation. We show that... 1. Galaxies in X-Ray Selected Clusters and Groups in Dark Energy Survey Data. I. Stellar Mass Growth of Bright Central Galaxies since z~1.2 Zhang, Y.; Miller, C.; McKay, T.; Rooney, P.; Evrard, A. E.; Romer, A. K.; Perfecto, R.; Song, J.; Desai, S.; Mohr, J.; Wilcox, H.; Bermeo-Hernandez, A.; Jeltema, T.; Hollowood, D.; Bacon, D.; Capozzi, D.; Collins, C.; Das, R.; Gerdes, D.; Hennig, C.; Hilton, M.; Hoyle, B.; Kay, S.; Liddle, A.; Mann, R. G.; Mehrtens, N.; Nichol, R. C.; Papovich, C.; Sahlén, M.; Soares-Santos, M.; Stott, J.; Viana, P. T.; Abbott, T.; Abdalla, F. B.; Banerji, M.; Bauer, A. H.; Benoit-Lévy, A.; Bertin, E.; Brooks, D.; Buckley-Geer, E.; Burke, D. L.; Carnero Rosell, A.; Castander, F. J.; Diehl, H. T.; Doel, P.; Cunha, C. E.; Eifler, T. F.; Fausti Neto, A.; Fernandez, E.; Flaugher, B.; Fosalba, P.; Frieman, J.; Gaztanaga, E.; Gruen, D.; Gruendl, R. A.; Honscheid, K.; James, D.; Kuehn, K.; Kuropatkin, N.; Lahav, O.; Maia, M. A. G.; Makler, M.; Marshall, J. L.; Martini, Paul; Miquel, R.; Ogando, R.; Plazas, A. A.; Roodman, A.; Rykoff, E. S.; Sako, M.; Sanchez, E.; Scarpine, V.; Schubnell, M.; Sevilla, I.; Smith, R. C.; Sobreira, F.; Suchyta, E.; Swanson, M. E. C.; Tarle, G.; Thaler, J.; Tucker, D.; Vikram, V.; da Costa, L. N. 2016-01-01 Using the science verification data of the Dark Energy Survey for a new sample of 106 X-ray selected clusters and groups, we study the stellar mass growth of bright central galaxies (BCGs) since redshift z ~ 1.2. Compared with the expectation in a semi-analytical model applied to the Millennium Simulation, the observed BCGs become under-massive/under-luminous with decreasing redshift. We incorporate the uncertainties associated with cluster mass, redshift, and BCG stellar mass measurements into an analysis of a redshift-dependent BCG-cluster mass relation, {m}*∝ ({M}200}/{1.5×{10}14{M}⊙}) 0.24+/-0.08(1+z)-0.19+/- 0.34, and compare the observed relation to the model prediction. We estimate the average growth rate since z = 1.0 for BCGs hosted by clusters of M200,z = 1013.8 M⊙ at z = 1.0: m*,BCG appears to have grown by 0.13 ± 0.11 dex, in tension at the ˜2.5σ significance level with the 0.40 dex growth rate expected from the semi-analytic model. We show that the build-up of extended intracluster light after z = 1.0 may alleviate this tension in BCG growth rates. 2. CARMA Survey Toward Infrared-bright Nearby Galaxies (STING) II: Molecular Gas Star Formation Law and Depletion Time Across the Blue Sequence Rahman, Nurur; Xue, Rui; Wong, Tony; Leroy, Adam K; Walter, Fabian; Bigiel, Frank; Rosolowsky, Erik; Fisher, David B; Vogel, Stuart N; Blitz, Leo; West, Andrew A; Ott, Juergen 2011-01-01 We present an analysis of the relationship between molecular gas and current star formation rate surface density at sub-kpc and kpc scales in a sample of 14 nearby star-forming galaxies. Measuring the relationship in the bright, high molecular gas surface density ($\\Shtwo\\gtrsim$20 \\msunpc) regions of the disks to minimize the contribution from diffuse extended emission, we find an approximately linear relation between molecular gas and star formation rate surface density,$\

3. Spitzer bright, UltraVISTA faint sources in COSMOS: the contribution to the overall population of massive galaxies at z=3-7

Caputi, K I; Laigle, C; McCracken, H J; Fevre, O Le; Fynbo, J; Milvang-Jensen, B; Capak, P; Salvato, M; Taniguchi, Y

2015-01-01

We have analysed a sample of 574 Spitzer 4.5 micron-selected galaxies with [4.5]24 (AB) over the UltraVISTA ultra-deep COSMOS field. Our aim is to investigate whether these mid-IR bright, near-IR faint sources contribute significantly to the overall population of massive galaxies at redshifts z>=3. By performing a spectral energy distribution (SED) analysis using up to 30 photometric bands, we have determined that the redshift distribution of our sample peaks at redshifts z~2.5-3.0, and ~32% of the galaxies lie at z>=3. We have studied the contribution of these sources to the galaxy stellar mass function (GSMF) at high redshifts. We found that the [4.5]24 galaxies produce a negligible change to the GSMF previously determined for Ks~50% of the galaxies with stellar masses Mst>~6 x 10^10 Msun. We also constrained the GSMF at the highest-mass end (Mst>~2 x 10^11 Msun) at z>=5. From their presence at 5=

4. The Tolman Surface Brightness Test for the Reality of the Expansion. III. HST Profile and Surface Brightness Data for Early-Type Galaxies in Three High-Redshift Clusters

Lubin, L M; Lubin, Lori M.; Sandage, Allan

2001-01-01

Photometric data for 34 early-type galaxies in the three high-redshift clusters Cl 1324+3011 (z = 0.76), Cl 1604+4304 (z = 0.90), and Cl 1604+4321 (z = 0.92), observed with the Hubble Space Telescope (HST) and with the Keck 10-meter telescopes by Oke, Postman & Lubin, are analyzed to obtain the photometric parameters of mean surface brightness, magnitudes for the growth curves, and angular radii at various Petrosian eta radii. The angular radii at eta = 1.3 mag for the program galaxies are all larger than 0.24". All of the galaxies are well resolved at this angular size using HST whose point-spread function is 0.05", half width at half maximum. The data for each of the program galaxies are listed at eta = 1.0, 1.3, 1.5, 1.7, and 2.0 mag. They are corrected by color equations and K terms for the effects of redshift to the rest-frame Cape/Cousins I for Cl 1324+3011 and Cl 1604+4304 and R for Cl 1604+4321. The K corrections are calculated from synthetic spectral energy distributions derived from evolving ste...

5. Atmospheric CO2 remote sensing system based on high brightness semiconductor lasers and single photon counting detection

Pérez-Serrano, Antonio; Vilera, Maria Fernanda; Esquivias, Ignacio; Faugeron, Mickael; Krakowski, Michel; van Dijk, Frédéric; Kochem, Gerd; Traub, Martin; Adamiec, Pawel; Barbero, Juan; Ai, Xiao; Rarity, John G.; Quatrevalet, Mathieu; Ehret, Gerhard

2015-10-01

We propose an integrated path differential absorption lidar system based on all-semiconductor laser sources and single photon counting detection for column-averaged measurements of atmospheric CO2. The Random Modulated Continuous Wave (RM-CW) approach has been selected as the best suited to semiconductor lasers. In a RM-CW lidar, a pseudo random sequence is sent to the atmosphere and the received signal reflected from the target is correlated with the original sequence in order to retrieve the path length. The transmitter design is based on two monolithic Master Oscillator Power Amplifiers (MOPAs), providing the on-line and off-line wavelengths close to the selected absorption line around 1.57 µm. Each MOPA consists of a frequency stabilized distributed feedback master oscillator, a bent modulator section, and a tapered amplifier. This design allows the emitters to deliver high power and high quality laser beams with good spectral properties. An output power above 400 mW with a SMSR higher than 45 dB and modulation capability have been demonstrated. On the side of the receiver, our theoretical and experimental results indicate that the major noise contribution comes from the ambient light and detector noise. For this reason narrow band optical filters are required in the envisioned space-borne applications. In this contribution, we present the latest progresses regarding the design, modeling and characterization of the transmitter, the receiver, the frequency stabilization unit and the complete system.

6. MOIRCS Deep Survey. I: DRG Number Counts

Kajisawa, M; Suzuki, R; Tokoku, C; Uchimoto, Y K; Yoshikawa, T; Akiyama, M; Ichikawa, T; Ouchi, M; Omata, K; Tanaka, I; Nishimura, T; Yamada, T; Kajisawa, Masaru; Konishi, Masahiro; Suzuki, Ryuji; Tokoku, Chihiro; Uchimoto, Yuka Katsuno; Yoshikawa, Tomohiro; Akiyama, Masayuki; Ichikawa, Takashi; Ouchi, Masami; Omata, Koji; Tanaka, Ichi; Nishimura, Tetsuo; Yamada, Toru

2006-01-01

We use very deep near-infrared imaging data taken with Multi-Object InfraRed Camera and Spectrograph (MOIRCS) on the Subaru Telescope to investigate the number counts of Distant Red Galaxies (DRGs). We have observed a 4x7 arcmin^2 field in the Great Observatories Origins Deep Survey North (GOODS-N), and our data reach J=24.6 and K=23.2 (5sigma, Vega magnitude). The surface density of DRGs selected by J-K>2.3 is 2.35+-0.31 arcmin^-2 at K22 is smaller than that expected from the number counts at the brighter magnitude. The result indicates that while there are many bright galaxies at 222 suggest that the mass-dependent color distribution, where most of low-mass galaxies are blue while more massive galaxies tend to have redder colors, had already been established at that epoch.

7. MOIRCS Deep Survey. I: DRG Number Counts

Kajisawa, Masaru; Konishi, Masahiro; Suzuki, Ryuji; Tokoku, Chihiro; Uchimoto, Yuka; Katsuno; Yoshikawa, Tomohiro; Akiyama, Masayuki; Ichikawa, Takashi; Ouchi, Masami; Omata, Koji; Tanaka, Ichi; Nishimura, Tetsuo; Yamada, Toru

2006-12-01

We used very deep near-infrared imaging data taken with the Multi-Object InfraRed Camera and Spectrograph (MOIRCS) on the Subaru Telescope to investigate the number counts of Distant Red Galaxies (DRGs). We observed a 4' × 7' field in the Great Observatories Origins Deep Survey-North (GOODS-N), and our data reached J=24.6 and K=23.2 (5σ, Vega magnitude). The surface density of DRGs selected by J - K > 2.3 is 2.35 ± 0.31 arcmin-2 at K 22 is smaller than that expected from the number counts at the brighter magnitude. The result indicates that while there are many bright galaxies at 2 22 suggest that the mass-dependent color distribution, where most of the low-mass galaxies are blue, while more massive galaxies tend to have redder colors, had already been established at that epoch.

8. Chemical and luminosity evolution, and counts of galaxies in a merger model

Colin, P.; Schramm, D. N.

1993-01-01

A merger model is applied to the chemical and luminosity evolution of galaxies. Two aspects are focused on. The first is the problem of abundance ratios as a function of metallicity. The second is related to the luminosity evolution of galaxies. In relation to the former, we calculate the evolution of several chemical elements exploring a broad space of possible star formation rates, including those derived using phenomenological arguments from a multiple merger galaxy formation scenario. We are able to reproduce the observed plateau in the ratio of the abundances of oxygen to iron versus metallicity as a direct consequence of one of the merging SFR used; we have utilized a standard Type II supernovae nucleosynthesis scenario coupled with a reasonable binary model for Type Ia supernovae and its consequent nucleosynthetic yields. Following the consequent luminosity effects in a straightforward way enables the estimation of the evolution of bolometric luminosity. We have used our recently developed code for photometric evolution of galaxies to make a preliminary computation of the number-magnitude relationship, assuming a standard picture of galaxy evolution, in the B and K bands.

9. Morphological Number Counts and Redshift Distributions to I = 25 from the Hubble Deep Fields Constraints on Cosmological Models from Early Type Galaxies

Phillipps, S; Couch, W J; Fernández-Soto, A; Bristow, P D; Odewahn, S C; Windhorst, R A; Lanzetta, K

2000-01-01

We combine magnitude and photometric redshift data on galaxies in the Hubble Deep Fields with morphological classifications in order to separate out the distributions for early type galaxies. The updated morphological galaxy number counts down to I = 25 and the corresponding redshift distributions are used as joint constraints on cosmological models, in particular on the values of the density parameter Omega_{0} and normalised cosmological constant Lambda_{0}. We find that an Einstein - de Sitter universe with simple passive evolution gives an excellent fit to the counts and redshift data at all magnitudes. An open, low Omega_{0}, model with no net evolution (and conservation of the number of ellipticals), which fits the counts equally well, is somewhat less successful, predicting slightly lower mean redshifts and, more significantly, the lack of a high--z tail. A number conserving model with a dominant contribution from Lambda_{0}, on the other hand, is far less successful, predicting a much narrower distrib...

10. New insights to the photometric structure of Blue Compact Dwarf Galaxies from deep Near-Infrared studies I. Observations, surface photometry and decomposition of surface brightness profiles

Noeske, K G; Cairos, L M; Fricke, K J

2003-01-01

(shortened) We analyze deep Near Infrared (NIR) broad band images for a sample of Blue Compact Dwarf Galaxies (BCDs), allowing for the quantitative study of their extended stellar low-surface brightness (LSB) host galaxies. NIR surface brightness profiles (SBPs) of the LSB hosts agree at large galactocentric radii with those from optical studies. At small to intermediate radii, however, the NIR data reveal for more than half of our sample a significant flattening of the exponential SBP of the LSB host. Such SBPs ("type V" SBPs, Binggeli & Cameron 1991) have rarely been detected in LSB hosts of BCDs at optical wavelengths, where the relative flux contribution of the starburst is stronger than in the NIR and can hide such central intensity depressions of the LSB host. The structural properties, frequency and physical origin of type V LSB SBPs in BCDs and other dwarf galaxies have not yet been systematically studied. Nevertheless, their occurrence in a significant fraction of BCDs would impose important new ...

11. CARMA SURVEY TOWARD INFRARED-BRIGHT NEARBY GALAXIES (STING). II. MOLECULAR GAS STAR FORMATION LAW AND DEPLETION TIME ACROSS THE BLUE SEQUENCE

We present an analysis of the relationship between molecular gas and current star formation rate surface density at sub-kiloparsec and kiloparsec scales in a sample of 14 nearby star-forming galaxies. Measuring the relationship in the bright, high molecular gas surface density (ΣH2∼>20 M☉ pc–2) regions of the disks to minimize the contribution from diffuse extended emission, we find an approximately linear relation between molecular gas and star formation rate surface density, Nmol ∼ 0.96 ± 0.16, with a molecular gas depletion time, τmoldep ∼ 2.30 ± 1.32 Gyr. We show that in the molecular regions of our galaxies there are no clear correlations between τmoldep and the free-fall and effective Jeans dynamical times throughout the sample. We do not find strong trends in the power-law index of the spatially resolved molecular gas star formation law or the molecular gas depletion time across the range of galactic stellar masses sampled (M* ∼ 109.7-1011.5 M☉). There is a trend, however, in global measurements that is particularly marked for low-mass galaxies. We suggest that this trend is probably due to the low surface brightness CO J = 1-0, and it is likely associated with changes in CO-to-H2 conversion factor.

12. An ALMA survey of submillimetre galaxies in the Extended Chandra Deep Field South: High resolution 870um source counts

Karim, Alexander; Hodge, Jackie; Smail, Ian; Walter, Fabian; Biggs, Andy; Simpson, James; Danielson, Alice; Alexander, David; Bertoldi, Frank; Chapman, Scott; Coppin, Kristen; Dannerbauer, Helmut; Edge, Alastair; Greve, Thomas; Ivison, Rob; Knudsen, Kirsten; Menten, Karl; Schinnerer, Eva; Wardlow, Julie; Weiß, Axel; van der Werf, Paul

2012-01-01

We report the first counts of faint submillimetre galaxies (SMG) in the 870-um band derived from arcsecond resolution observations with the Atacama Large Millimeter Array (ALMA). We have used ALMA to map a sample of 122 870-um-selected submillimetre sources drawn from the (0.5x0.5)deg^2 LABOCA Extended Chandra Deep Field South Submillimetre Survey (LESS). These ALMA maps have an average depth of sigma(870um)~0.4mJy, some ~3x deeper than the original LABOCA survey and critically the angular resolution is more than an order of magnitude higher, FWHM of ~1.5" compared to ~19" for the LABOCA discovery map. This combination of sensitivity and resolution allows us to precisely pin-point the SMGs contributing to the submillimetre sources from the LABOCA map, free from the effects of confusion. We show that our ALMA-derived SMG counts broadly agree with the submillimetre source counts from previous, lower-resolution single-dish surveys, demonstrating that the bulk of the submillimetre sources are not caused by blendi...

13. Gas density and X-ray surface brightness profiles of clusters of galaxies from dark matter halo potentials beyond the isothermal beta model

Suto, Y; Makino, N; Suto, Yasushi; Sasaki, Shin; Makino, Nobuyoshi

1998-01-01

We describe a theoretical framework to compute the cluster gas distribution in hydrostatic equilibrium embedded in a class of spherical dark matter halo potentials. Unlike the conventional isothermal $\\beta$-model, the present method provides a physical basis to directly probe the shape of dark matter halo from the observed X-ray surface brightness and temperature profiles of clusters of galaxies. Specifically, we examine the extent to which the resulting gas density and X-ray surface brightness profiles are sensitive to the inner slope of the dark matter halo density and other more realistic effects including the self-gravity of the gas and the polytropic equation of state. We also discuss a practical strategy to apply the present methodology to the actual cluster profiles from future X-ray observations.

14. The Tolman Surface Brightness Test for the Reality of the Expansion. IV. A Measurement of the Tolman Signal and the Luminosity Evolution of Early-Type Galaxies

Lubin, L M; Lubin, Lori M.; Sandage, Allan

2001-01-01

We review a sample of the early literature in which the reality of the expansion is discussed, explain Hubble's reticence to accept the expansion as real, and contrast the Tolman surface brightness test with three other modern tests. We search for the Tolman surface brightness depression with redshift using the Hubble Space Telescope (HST) data from Paper III for 34 early-type galaxies from the three clusters Cl 1324+3011 (z=0.76), Cl 1604+4304 (z=0.90), and Cl 1604+4321 (z=0.92). Depressions of the surface brightness relative to the zero-redshift fiducial lines in the mean surface brightness, log linear radius diagrams of Paper I are found for all three clusters. Expressed as the exponent, n, in 2.5 log (1 + z)^n mag, the value of n for all three clusters is n = 2.59 +/- 0.17 in the R band and 3.37 +/- 0.13 in the I band for a q_o = 1/2 model. The sensitivity of the result to the assumed value of q_o is shown to be less than 23% between q_o = 0 and +1. For a true Tolman signal with n = 4, the luminosity evol...

15. Bright galaxies at z=9-11 from pure-parallel HST observations: Building a unique sample for JWST with Spitzer/IRAC

Bernard, Stephanie; Trenti, Michele; Bouwens, Rychard

2016-08-01

The combination of observations taken by Hubble and Spitzer revealed the unexpected presence of sources as bright as our own Milky Way as early as 400 Myr after the Big Bang, potentially highlighting a new highly efficient regime for star formation in L>L* galaxies at very early times. Yet, the sample of high-quality z>8 galaxies that have both HST and Spitzer/IRAC imaging is still very small, particularly at high luminosities. We propose here to remedy this situation and efficiently follow-up with Spitzer/IRAC the most promising z>8 sources from our Hubble Brightest of Reionizing Galaxies (BoRG) survey, which covers a footprint on the sky similar to CANDELS, provides a deeper search than ground-based surveys like UltraVISTA, and is robust against cosmic variance because of its 180 independent lines of sight. The proposed new 3.6 micron observations will continue the Spitzer cycle 12 BORG911 program and target 15 additional fields, leveraging over 300 new HST orbits (350 sqarcmin) to identify a final sample of about 5 to 10 bright galaxies at z >= 8.5. For optimal time use (just over 22 hours), our goal is to readily discriminate between z>8 sources (undetected or marginally detected in IRAC) and z~2 interlopers (strongly detected in IRAC) with just 1-2 hours per pointing. The high-quality candidates that we will identify with IRAC will be ideal targets for further studies to investigate the reionization state of the inter-galactic medium through near-IR Keck/VLT spectroscopy. They will also be uniquely suited to measurement of the redshift and stellar population properties through JWST/NIRSPEC observations, with the potential to elucidate how the first generations of stars are assembled in the earliest stages of the epoch of reionization.

16. Hα Surface Brightness Profiles of Star-Forming Galaxies and Dependence on Halo Mass Using the HAGGIS Survey

Kulkarni, S.; Wilman, D.; Erwin, P.; Koppenhöfer, J.; Gutierrez, L.; Beckman, J.; Saglia, R.; Bender, R.

2014-03-01

We present the first results from the Hα Galaxy Groups Imaging Survey (HAGGIS), a narrow-band imaging survey of SDSS groups at z Issac Newton Telescope (INT). In total, we observed 100 galaxy groups with a wide range of halo mass (1012 - 1014 M⊙) in pairs of narrow-band filters selected to get continuum subtracted rest-frame Hα images for each galaxy. The excellent data allows us to detect Hα down to the 10-18 ergs/s/cm2/arcsec2 level. Here, we examine the role played by halo mass and galaxy stellar mass in deciding the overall star formation activity in star forming disks by comparing stacked Hα profiles of galaxies in different halo mass and stellar mass bins. With this preliminary study, we have found that the star-formation activity in star-forming galaxies decreases in larger halos compared to the field galaxies. Using median equivalent width profiles, we can infer how environmental processes affect star-forming galaxies differently at different radii.

17. Comparing galaxy morphology and star formation properties in X-ray bright and faint groups and clusters

Roberts, Ian D.; Parker, Laura C.; Karunakaran, Ananthan

2016-02-01

Galaxy morphologies and star formation rates depend on environment. Galaxies in underdense regions are generally star-forming and discy whereas galaxies in overdense regions tend to be early-type and not actively forming stars. The mechanism(s) responsible for star formation quenching and morphological transformation remain unclear, although many processes have been proposed. We study the dependence of star formation and morphology on X-ray luminosity for galaxies in Sloan Digital Sky Survey Data Release 7 (SDSS-DR7) groups and clusters. While controlling for stellar and halo mass dependences, we find that galaxies in X-ray strong groups and clusters have preferentially low star-forming and disc fractions - with the differences being strongest at low stellar masses. The trends that we observe do not change when considering only galaxies found within or outside of the X-ray radius of the host group. When considering central and satellite galaxies separately we find that this dependence on X-ray luminosity is only present for satellites, and we show that our results are consistent with `galaxy strangulation' as a mechanism for quenching these satellites. We investigate the dynamics of the groups and clusters in the sample, and find that the velocity distributions of galaxies beyond the virial radius in low X-ray luminosity haloes tend to be less Gaussian in nature than the rest of the data set. This may be indicative of low X-ray luminosity groups and clusters having enhanced populations of star-forming and disc galaxies as a result of recent accretion.

18. zCOSMOS 10k-bright spectroscopic sample: exploring mass and environment dependence in early-type galaxies

Moresco, M; Cimatti, A; Zamorani, G; Mignoli, M; Di Cesare, S; Bolzonella, M; Zucca, E; Lilly, S; Kovac, K; Scodeggio, M; Cassata, P; Tasca, L; Vergani, D; Halliday, C; Carollo, M; Contini, T; Kneib, J -P; Le Fèvre, O; Mainieri, V; Renzini, A; Bardelli, S; Bongiorno, A; Caputi, K; Coppa, G; Cucciati, O; de la Torre, S; de Ravel, L; Franzetti, P; Garilli, B; Iovino, A; Kampczyk, P; Knobel, C; Lamareille, F; Le Borgne, J F; Le Brun, V; Maier, C; Pello, R; Peng, Y; Montero, E Perez; Ricciardelli, E; Silverman, J D; Tanaka, M; Tresse, L; Abbas, U; Bottini, D; Cappi, A; Guzzo, L; Koekemoer, A M; Leauthaud, A; Maccagni, D; Marinoni, C; McCracken, H J; Memeo, P; Meneux, B; Nair, P; Oesch, P; Porciani, C; Scaramella, R; Scarlata, C; Scoville, N

2010-01-01

We present the analysis of the U-V rest-frame color distribution and some spectral features as a function of mass and environment for two sample of early-type galaxies up to z=1 extracted from the zCOSMOS spectroscopic survey. The first sample ("red galaxies") is defined with a photometric classification, while the second ("ETGs") by combining morphological, photometric, and spectroscopic properties to obtain a more reliable sample. We find that the color distribution of red galaxies is not strongly dependent on environment for all mass bins, with galaxies in overdense regions redder than galaxies in underdense regions with a difference of 0.027\\pm0.008 mag. The dependence on mass is far more significant, with average colors of massive galaxies redder by 0.093\\pm0.007 mag than low-mass galaxies throughout the entire redshift range. We study the color-mass relation, finding a mean slope 0.12\\pm0.005, while the color-environment relation is flatter, with a slope always smaller than 0.04. The spectral analysis t...

19. Faint Submillimeter Galaxies Revealed by Multifield Deep ALMA Observations: Number Counts, Spatial Clustering, and Dark Submillimeter Emitters

Ono, Yoshiaki; Kurono, Yasutaka; Momose, Rieko

2014-01-01

We present the statistics of faint submillimeter/millimeter galaxies (SMGs) and serendipitous detections of submillimeter/millimeter emitters (SMEs) with no multi-wavelength continuum counterpart revealed by the deep ALMA observations. We identify faint SMGs with flux densities of 0.1-1.0 mJy in the deep Band 6 and Band 7 maps of 10 independent fields that reduce cosmic variance effects. The differential number counts at 1.2 mm are found to increase with decreasing flux density down to 0.1 mJy. Our number counts indicate that the faint (0.1-1.0 mJy, or SFR_IR ~ 30-300 Msun/yr) SMGs contribute nearly a half of the extragalactic background light (EBL), while the remaining half of the EBL is mostly contributed by very faint sources with flux densities of 1 mJy) SMGs, but comparable with abundant high-z star-forming populations such as sBzKs, LBGs, and LAEs. Finally, we report the serendipitous detections of SMEs with continuum counterparts neither in our 1.2 mm-band nor multi-wavelength images including ultra de...

20. The LBT Bootes Field Survey: I. The Rest-frame UV and Luminosity Functions and Clustering of Bright Lyman Break Galaxies at z~3

Bian, Fuyan; Jiang, Linhua; McGreer, Ian; Dey, Arjun; Green, Richard; Maiolino, Roberto; Walter, Fabian; Lee, Kyoung-Soo; Dave, Romeel

2013-01-01

We present a deep LBT/LBC U-band imaging survey (9 deg2) covering the NOAO Bootes field. A total of 14,485 Lyman Break Galaxies (LBGs) at z~3 are selected, which are used to measure the rest-frame UV luminosity function (LF). The large sample size and survey area reduce the LF uncertainties due to Poisson statistics and cosmic variance by >3 compared to previous studies. At the bright end, the LF shows excess power compared to the best-fit Schechter function, which can be attributed to the contribution of $z\\sim3$ quasars. We compute the rest-frame near-infrared LF and stellar mass function (SMF) of z~3 LBGs based on the R-band and IRAC [4.5 micro m]-band flux relation. We investigate the evolution of the UV LFs and SMFs between z~7 and z~3, which supports a rising star formation history in the LBGs. We study the spatial correlation function of two bright LBG samples and estimate their average host halo mass. We find a tight relation between the host halo mass and the galaxy star formation rate (SFR),which fo...

1. The faint galaxy contribution to the diffuse extragalactic background light

Cole, Shaun; Treyer, Marie-Agnes; Silk, Joseph

1992-01-01

Models of the faint galaxy contribution to the diffuse extragalactic background light are presented, which are consistent with current data on faint galaxy number counts and redshifts. The autocorrelation function of surface brightness fluctuations in the extragalactic diffuse light is predicted, and the way in which these predictions depend on the cosmological model and assumptions of biasing is determined. It is confirmed that the recent deep infrared number counts are most compatible with a high density universe (Omega-0 is approximately equal to 1) and that the steep blue counts then require an extra population of rapidly evolving blue galaxies. The faintest presently detectable galaxies produce an interesting contribution to the extragalactic diffuse light, and still fainter galaxies may also produce a significant contribution. These faint galaxies still only produce a small fraction of the total optical diffuse background light, but on scales of a few arcminutes to a few degrees, they produce a substantial fraction of the fluctuations in the diffuse light.

2. The bimodality of the 10k zCOSMOS-bright galaxies up to z ~ 1: a new statistical and portable classification based on the global optical galaxy properties

Coppa, G; Zamorani, G; Bardelli, S; Bolzonella, M; Pozzetti, L; Vergani, D; Zucca, E; Cimatti, A; Lilly, S J; Carollo, C M; Contini, T; Le Fèvre, O; Renzini, A; Scodeggio, M; Mainieri, V; Bongiorno, A; Caputi, K; Cucciati, O; de la Torre, S; de Ravel, L; Franzetti, P; Garilli, B; Memeo, P; Iovino, A; Kampczyk, P; Kneib, J -P; Knobel, C; Koekemoer, A M; Kovac, K; Lamareille, F; Le Borgne, J F; Le Brun, V; Maier, C; Pellò, R; Peng, Y; Perez-Montero, E; Ricciardelli, E; Scarlata, C; Silverman, J D; Tanaka, M; Tasca, L; Tresse, L; Abbas, U; Bottini, D; Capak, P; Cappi, A; Cassata, P; Fumana, M; Guzzo, L; Leauthaud, A; Maccagni, D; Marinoni, C; Meneux, B; Oesch, P; Porciani, C; Scaramella, R; Scoville, N

2010-01-01

Our goal is to develop a new and reliable statistical method to classify galaxies from large surveys. We probe the reliability of the method by comparing it with a three-dimensional classification cube (Mignoli et al.~2009), using the same set of spectral, photometric and morphological parameters.We applied two different methods of classification to a sample of galaxies extracted from the zCOSMOS redshift survey, in the redshift range 0.5 0.5$, while galaxies with lower masses - of the order of$10^{10}$Msun - are in transition at later epochs; galaxies with$M 5\\cdot 10^{10}$Msun) mostly completed their transition before$z\\sim 1$. 3. The UBVRI light curve behaviour of the Seyfert galaxy NGC 4151 during the extraordinary maximum of the nuclear brightness in 1989-1997 Merkulova, N. I. Observations were carried out with the 1.25 m telescope of Crimean Astrophysical Observatory, equipped with a Double Image Chopping Photometer--Polarimeter by Prof. V.Piirola from Helsinki University. This device allows to obtain simultaneous observations in 5 filters of Johnson's UBVRI system. Photometric errors were less than 0,m01, time resolution was about 3--4 min. Round diaphragms with diameters 20 and 15 arcseconds were used. During this extraordinary maximum the nuclear brightness in the U band increases on ~2m.0, while in the I band -- only on ~ 0m.7. All colour indices decreased: (U-B) from ~-0m.3 to ~-0m.8, (B-V) from ~0m.9 to ~0m.4, (V-I) from ~1m.3 to ~0m.9. The flux ascending in the blue spectral region was twice more than in the red one. The galaxy nucleus seems to be more and more "bluer", but some brightness and colour variations were observed during each of the 9 observational seasons, include local mimimums, flares and intranight variability. Colour--magnitude dependences were analyzed as well as two--colour diagrams. There were no differences between data obtained in 20" and 15" apertures. This fact means that we can see only fluxes from the galactic nucleus during the epoch of brightness maximum. 4. OPTICAL-FAINT, FAR-INFRARED-BRIGHT HERSCHEL SOURCES IN THE CANDELS FIELDS: ULTRA-LUMINOUS INFRARED GALAXIES AT z > 1 AND THE EFFECT OF SOURCE BLENDING Yan, Haojing; Stefanon, Mauro; Ma, Zhiyuan [Department of Physics and Astronomy, University of Missouri, Columbia, MO 65211 (United States); Willner, S. P.; Ashby, Matthew L. N. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Somerville, Rachel [Department of Physics and Astronomy, Rutgers University, 136 Frelinghuysen Road, Piscataway, NJ 08854 (United States); Davé, Romeel [University of the Western Cape, 7535 Bellville, Cape Town (South Africa); Pérez-González, Pablo G. [Departamento de Astrofísica, Facultad de CC. Físicas, Universidad Complutense de Madrid, E-28040 Madrid (Spain); Cava, Antonio [Observatoire de Genève, Université de Genève, 51 Ch. des Maillettes, 1290 Versoix (Switzerland); Wiklind, Tommy [Joint ALMA Observatory, Alonso de Cordova 3107, Vitacura, Santiago (Chile); Kocevski, Dale [Department of Physics and Astronomy, University of Kentucky, Lexington, KY 40506 (United States); Rafelski, Marc [Infrared Processing and Analysis Center, California Institute of Technology, Pasadena, CA 91125 (United States); Kartaltepe, Jeyhan [National Optical Astronomy Observatory, 950 North Cherry Avenue, Tucson, AZ 85719 (United States); Cooray, Asantha [Department of Physics and Astronomy, University of California, Irvine, CA 92697 (United States); Koekemoer, Anton M.; Grogin, Norman A. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States) 2014-07-01 The Herschel very wide field surveys have charted hundreds of square degrees in multiple far-IR (FIR) bands. While the Sloan Digital Sky Survey (SDSS) is currently the best resource for optical counterpart identifications over such wide areas, it does not detect a large number of Herschel FIR sources and leaves their nature undetermined. As a test case, we studied seven ''SDSS-invisible'', very bright 250 μm sources (S {sub 250} > 55 mJy) in the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey fields where we have a rich multi-wavelength data set. We took a new approach to decompose the FIR sources, using the near-IR or the optical images directly for position priors. This is an improvement over the previous decomposition efforts where the priors are from mid-IR data that still suffer from the problem of source blending. We found that in most cases the single Herschel sources are made of multiple components that are not necessarily at the same redshifts. Our decomposition succeeded in identifying and extracting their major contributors. We show that these are all ultra-luminous infrared galaxies at z ∼ 1-2 whose high L {sub IR} is mainly due to dust-obscured star formation. Most of them would not be selected as submillimeter galaxies. They all have complicated morphologies indicative of mergers or violent instability, and their stellar populations are heterogeneous in terms of stellar masses, ages, and formation histories. Their current ultra-luminous infrared galaxy phases are of various degrees of importance in their stellar mass assembly. Our practice provides a promising starting point for developing an automatic routine to reliably study bright Herschel sources. 5. OPTICAL-FAINT, FAR-INFRARED-BRIGHT HERSCHEL SOURCES IN THE CANDELS FIELDS: ULTRA-LUMINOUS INFRARED GALAXIES AT z > 1 AND THE EFFECT OF SOURCE BLENDING The Herschel very wide field surveys have charted hundreds of square degrees in multiple far-IR (FIR) bands. While the Sloan Digital Sky Survey (SDSS) is currently the best resource for optical counterpart identifications over such wide areas, it does not detect a large number of Herschel FIR sources and leaves their nature undetermined. As a test case, we studied seven ''SDSS-invisible'', very bright 250 μm sources (S 250 > 55 mJy) in the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey fields where we have a rich multi-wavelength data set. We took a new approach to decompose the FIR sources, using the near-IR or the optical images directly for position priors. This is an improvement over the previous decomposition efforts where the priors are from mid-IR data that still suffer from the problem of source blending. We found that in most cases the single Herschel sources are made of multiple components that are not necessarily at the same redshifts. Our decomposition succeeded in identifying and extracting their major contributors. We show that these are all ultra-luminous infrared galaxies at z ∼ 1-2 whose high L IR is mainly due to dust-obscured star formation. Most of them would not be selected as submillimeter galaxies. They all have complicated morphologies indicative of mergers or violent instability, and their stellar populations are heterogeneous in terms of stellar masses, ages, and formation histories. Their current ultra-luminous infrared galaxy phases are of various degrees of importance in their stellar mass assembly. Our practice provides a promising starting point for developing an automatic routine to reliably study bright Herschel sources 6. Evidence for Ubiquitous, High-EW Nebular Emission in z~7 Galaxies: Towards a Clean Measurement of the Specific Star Formation Rate using a Sample of Bright, Magnified Galaxies Smit, R; Labbe, I; Zheng, W; Bradley, L; Donahue, M; Lemze, D; Moustakas, J; Umetsu, K; Zitrin, A; Coe, D; Postman, M; Gonzalez, V; Bartelmann, M; Benitez, N; Broadhurst, T; Ford, H; Grillo, C; Infante, L; Jimenez-Teja, Y; Jouvel, S; Kelson, D D; Lahav, O; Maoz, D; Medezinski, E; Melchior, P; Meneghetti, M; Merten, J; Molino, A; Moustakas, L; Nonino, M; Rosati, P; Seitz, S 2013-01-01 Growing observational evidence now indicates that nebular line emission has a significant impact on the rest-frame optical fluxes of z~5-7 galaxies observed with Spitzer. This line emission makes z~5-7 galaxies appear more massive, with lower specific star formation rates. However, corrections for this line emission have been very difficult to perform reliably due to huge uncertainties on the overall strength of such emission at z>~5.5. Here, we present the most direct observational evidence yet for ubiquitous high-EW [OIII]+Hbeta line emission in Lyman-break galaxies at z~7, while also presenting a strategy for an improved measurement of the sSFR at z~7. We accomplish this through the selection of bright galaxies in the narrow redshift window z~6.6-7.0 where the IRAC 4.5 micron flux provides a clean measurement of the stellar continuum light. Observed 4.5 micron fluxes in this window contrast with the 3.6 micron fluxes which are contaminated by the prominent [OIII]+Hbeta lines. To ensure a high S/N for our I... 7. H-Band dropouts in the deepest CANDELS field. A new population of bright massive galaxies at z >3 Alcalde Pampliega, B.; Pérez-González, P. G.; Domínguez Sánchez, H.; Esquej, P.; Eliche-Moral, M. C.; Barro, G. 2015-05-01 The recent increase in depth, spatial and wavelength coverage of extragalactic surveys has improved dramatically our understanding of galaxy formation and evolution and is revealing a new population of galaxies at high redshift. That is consistent with a downsizing (Cowie, L. L., Songaila, A., Hu, E. M., & Cohen, J. G. 1996, AJ, 112, 839; Heavens, A., Panter, B., Jiménez, R., & Dunlop, J. 2004, Nature, 428, 625; Juneau, S., et al. 2005, ApJ, 619, L135; Bauer, A. E., Drory, N., Hill, G. J., & Feulner, G. 2005, ApJ, 621, L89; Pérez-González et al. 2008, ApJ, 675, 234) scenario, which implies that the most massive galaxies formed early in the history of the universe and evolved quickly. Red color criteria and the analysis of deep mid-IR, has been proven to very useful to identify high-z extremely red galaxies as shown in (Caputi, K. et al. 2012, ApJ, 750, L20 and Huang, J.-S., Zheng, X. Z., Rigopoulou, D. et al., 2011, ApJ, 742, L13). We present our analysis of the deepest near-infrared (F160W/H-band from CANDELS) and mid-infrared (IRAC from GOODS) data taken by HST and Spitzer (in the GOODS fields) to select sources only detected by IRAC and with no CANDELS counterpart (i.e., H>27, [3.6]≤25). These H-Band dropouts constitute a previously unknown population of dust-enshrouded and/or quiescent massive red galaxies at z>3. Using the wealth of data available in the GOODS field, especially the SHARDS data, we characterize the properties of this population of red galaxies and discuss on its relevance for previous estimations of the stellar mass function at z=3-5, and the evolution of massive galaxies in the early Universe. 8. {\\em Herschel}-ATLAS/GAMA: The Environmental Density of Far-Infrared Bright Galaxies at$z \\leq 0.5$Burton, C S; Smith, D J B; Bonfield, D G; Hardcastle, M J; Stevens, J A; Bourne, N; Baes, M; Brough, S; Cava, A; Cooray, A; Dariush, A; De Zotti, G; Dunne, L; Eales, S; Hopwood, R; Ibar, E; Ivison, R J; Liske, J; Loveday, J; Maddox, S J; Negrello, M; Smith, M W L; Valiante, E 2013-01-01 We compare the environmental and star formation properties of far-infrared detected and non--far-infrared detected galaxies out to$z \\sim0.5$. Using optical spectroscopy and photometry from the Galaxy And Mass Assembly (GAMA) and Sloan Digital Sky Survey (SDSS), with far-infrared observations from the {\\em Herschel}-ATLAS Science Demonstration Phase (SDP), we apply the technique of Voronoi Tessellations to analyse the environmental densities of individual galaxies. Applying statistical analyses to colour,$r-$band magnitude and redshift-matched samples, we show there to be a significant difference at the 3.5$\\sigma$level between the normalized environmental densities of these two populations. This is such that infrared emission (a tracer of star formation activity) favours underdense regions compared to those inhabited by exclusively optically observed galaxies selected to be of the same$r-\$band magnitude, colour and redshift. Thus more highly star-forming galaxies are found to reside in the most underdens...

9. Evidence for ubiquitous high-equivalent-width nebular emission in z ∼ 7 galaxies: toward a clean measurement of the specific star-formation rate using a sample of bright, magnified galaxies

Smit, R.; Bouwens, R. J.; Labbé, I. [Leiden Observatory, Leiden University, NL-2300 RA Leiden (Netherlands); Zheng, W.; Lemze, D.; Ford, H. [Department of Physics and Astronomy, The Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218 (United States); Bradley, L.; Coe, D.; Postman, M. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21208 (United States); Donahue, M. [Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824 (United States); Moustakas, J. [Siena College, 515 Loudon Road, Loudonville, NY 12211 (United States); Umetsu, K. [Institute of Astronomy and Astrophysics, Academia Sinica, P. O. Box 23-141, Taipei 10617, Taiwan (China); Zitrin, A.; Bartelmann, M. [Institut fur Theoretische Astrophysik, ZAH, Albert-Ueberle-Straß e 2, 69120 Heidelberg (Germany); Gonzalez, V. [Department of Physics and Astronomy, University of California, Riverside, CA 92521 (United States); Benítez, N.; Jimenez-Teja, Y. [Instituto de Astrofisica de Andalucia (CSIC), C/Camino Bajo de Huetor 24, Granada 18008 (Spain); Broadhurst, T. [Department of Theoretical Physics, University of the Basque Country, P. O. Box 644, 48080 Bilbao (Spain); Grillo, C. [Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, DK-2100 Copenhagen (Denmark); Infante, L. [Departamento de Astronoia y Astrofisica, Pontificia Universidad Catolica de Chile, V. Mackenna 4860, Santiago 22 (Chile); and others

2014-03-20

Growing observational evidence indicates that nebular line emission has a significant impact on the rest-frame optical fluxes of z ∼ 5-7 galaxies. This line emission makes z ∼ 5-7 galaxies appear more massive, with lower specific star-formation rates (sSFRs). However, corrections for this line emission have been difficult to perform reliably because of huge uncertainties on the strength of such emission at z ≳ 5.5. In this paper, we present the most direct observational evidence thus far for ubiquitous high-equivalent-width (EW) [O III] + Hβ line emission in Lyman-break galaxies at z ∼ 7, and we present a strategy for an improved measurement of the sSFR at z ∼ 7. We accomplish this through the selection of bright galaxies in the narrow redshift window z ∼ 6.6-7.0 where the Spitzer/Infrared Array Camera (IRAC) 4.5 μm flux provides a clean measurement of the stellar continuum light, in contrast with the 3.6 μm flux, which is contaminated by the prominent [O III] + Hβ lines. To ensure a high signal-to-noise ratio for our IRAC flux measurements, we consider only the brightest (H {sub 160} < 26 mag) magnified galaxies we have identified behind galaxy clusters. It is remarkable that the mean rest-frame optical color for our bright seven-source sample is very blue, [3.6]-[4.5] = –0.9 ± 0.3. Such blue colors cannot be explained by the stellar continuum light and require that the rest-frame EW of [O III] + Hβ is greater than 637 Å for the average source. The four bluest sources from our seven-source sample require an even more extreme EW of 1582 Å. We can also set a robust lower limit of ≳ 4 Gyr{sup –1} on the sSFR of our sample based on the mean spectral energy distribution.

10. VLBI observations of the nuclei of a mixed sample of bright galaxies and quasars at 327 MHz

The first VLBI observations using the Ooty telescope are presented. An array consisting of telescopes at Ooty (India), Crimea (USSR), Torun (Poland), Westerbork (Netherlands) and Jodrell Bank (United Kingdom) was operated in 1983 December at a frequency of 327 MHz. Nearby galaxies, compact quasars and SS433 were observed in this pilot experiment. Most of the galaxies were found to be well resolved. The structure of SS433 (visible only on the shortest baseline) is consistent with that obtained in previous high-frequency VLBI work. The visibilities of the compact quasars indicate that large-scale scattering may be taking place in the interplanetary medium. (author)
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