2009 Fermi Symposium, Washington, D.C., Nov. 2-5 5
Figure 5: Ratio of γ-ray luminosity to submillimeter luminosity in the 1mm band. The location of an object in this
plot should be directly correlated with its blazar “state”, with FSRQs occupying the upper right and BL Lacs the lower
left. Flat-spectrum radio quasar 3C 454.3 is the object with the highest submillimeter luminosity in this plot.
•BL Lacs and FSRQs do not exhibit signiﬁcant
diﬀerences in amplitude of submillimeter vari-
ability or characteristic timescale, but our sam-
ple of BL Lacs may be dominated by high-
peaked BL Lacs (HBLs), which exhibit obser-
vational similarities with FSRQs.
•Blazar submillimeter light curves are consistent
with being produced by a single process that ac-
counts for both high and low states, with char-
acteristic timescales 10 <τrest < 500 days.
•The blazars detected byFermi have synchrotron
peaks at higher frequencies, regardless of sub-
millimeter luminosity.
•FSRQs exhibit higher ratios of γ-ray to sub-
millimeter luminosity than BL Lacs (Figure 5),
but all objects inhabit a region of parameter
space suggesting transitions between states dur-
ing ﬂaring epochs.
As Fermi continues to observe fainter sources, the
sample of objects for which we can perform this type of
analysis will increase and provide better limits on our
results. To understand the physical relevance of these
results, however, it is important to be able to distin-
guish between the diﬀerence in variability between BL
Lacs and FSRQs. One avenue for exploring this dif-
ference is to monitor changing submillimeter energy
spectral index and the ratio of γ-ray to submillime-
ter luminosity as functions of time. The full mean-
ing of the results of our autoregressive method is not
yet clear, and will require better-sampled blazar light
curves and the comparison between τrest with physical
timescales such as the synchrotron cooling timescale.
These analyses would allow us to place constraints
on the processes occurring near the base of the jet in
blazars and further understand the intimate connec-
tion between them.
Acknowledgments
This work was supported in part by the NSF
REU and DoD ASSURE programs under Grant no.
0754568 and by the Smithsonian Institution. Par-
tial support was also provided by NASA contract
NAS8-39073 and NASA grant NNX07AQ55G. We
have made use of the SIMBAD database, operated at
CDS, Strasbourg, France, and the NASA/IPAC Ex-
tragalactic Database (NED) which is operated by the
JPL, Caltech, under contract with NASA.
eConf C091122