4 2009 Fermi Symposium, Washington, D.C., Nov. 2-5
TABLE I: Fluxes and Signiﬁcance in High Energy Bands
50 - 100 keV 100 - 300 keV 300 - 500 keV
Flux Error Signif. Flux Error Signif. Flux Error Signif.
(mCrab) (mCrab) (σ) (mCrab) (mCrab) (σ) (mCrab) (mCrab) (σ)
Crab 1000 3 336 1000 6 182 1000 47 21.2
Cen A 72 4 18 108 7 15 42 47 0.9
Cyg X-1 1130 4 283 1094 8 137 474 50 9.5
GRS 1915+105 121 4 30 49 7 7 41 52 0.8
1E 1740-29 113 5 23 96 10 10 97 68 1.4
SWIFT 1753.5-0127 135 5 27 151 9 17 131 64 2.0
XTE J1752-223 770 16 48 622 30 21 132 218 0.6
FIG. 6: 1E1740-29 light curve. Horizontal scale is in mod-
iﬁed Julian days.
will use the GBM CSPEC data with their ﬁner energy
bins to obtain a ﬁt to the spectrum and compare the
power law index to that measured by Integral.
SWIFT J1753.5-0127 (Fig. 7) is a LMXB with
the compact object likely being a black hole. Swift
discovered this source when it observed a large ﬂare
in July of 2005. The source did not return to qui-
escence but settled into a low intensity hard state
[14]. BATSE occultation measurements from 1991-
2000 showed no signiﬁcant emission from this source
above 25 keV [15]. The GBM results show that this
source is still in a hard state, with signiﬁcant emis-
sion above 100 keV. We will continue to monitor this
FIG. 7: SWIFTJ1753.5-0127 light curve. Horizontal scale
is in modiﬁed Julian days.
source while it is in the hard state, with longer obser-
vations potentially verifying signiﬁcant emission above
300 keV.
B. Transient Source
The new transient black hole candidate XTE
J1752-223 rose from undetectable on 2009 October
24 to 511 ± 50 mCrab (12 - 25 keV), 570 ± 70 mCrab
(25 - 50 keV), 970 ± 100 mCrab (50 - 100 keV), and
330 ± 100 mCrab (100 - 300 keV) on 2009 November
2 [2, 16]. The light curve is variable, especially in the
eConf C091122