TITLE:   GCN CIRCULAR
NUMBER:  10993
SUBJECT: GRB 100725B: Swift-BAT refined analysis
DATE:    10/07/26 12:37:13 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@lheamail.gsfc.nasa.gov>

T. Sakamoto (GSFC/UMBC), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC),
J. R. Cummings (GSFC/UMBC), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA),
C. B. Markwardt (GSFC/UMD), D. M. Palmer (LANL), M. Stamatikos (GSFC/ORAU),
J. Tueller (GSFC), T. N. Ukwatta (GWU)
(i.e. the Swift-BAT team):
 
Using the data set from T-240 to T+609 sec from recent telemetry downlinks,
we report further analysis of BAT GRB 100725B (trigger #429969)
(Baumgartner, et al., GCN Circ. 10983).  The BAT ground-calculated position is
RA, Dec = 290.029, 76.955 deg, which is 
   RA(J2000)  =  19h 20m 07.0s 
   Dec(J2000) = +76d 57' 17.6" 
with an uncertainty of 1.2 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 28%.
 
The mask-weighted light curve shows several peaks starting at ~T-10 sec, peaking
at ~T+10, T+60, T+90, T+130, and T+220 sec, and ending at ~T+240 sec.
T90 (15-350 keV) is 200 +- 30 sec (estimated error including systematics).
 
The time-averaged spectrum from T-4.8 to T+226.1 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.89 +- 0.06.  The fluence in the 15-150 keV band is 6.8 +- 0.2 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+132.41 sec in the 15-150 keV band
is 2.4 +- 0.1 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level. 
 
The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/429969/BA/