TITLE:   GCN CIRCULAR
NUMBER:  15457
SUBJECT: GRB 131103A: Swift-BAT refined analysis
DATE:    13/11/05 16:40:45 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott@lheamail.gsfc.nasa.gov>

S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), J. R. Cummings (GSFC/UMBC),
N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), A. Y. Lien (NASA/UMBC),
C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (AGU),
M. Stamatikos (OSU), J. Tueller (GSFC), T. N. Ukwatta (MSU)
(i.e. the Swift-BAT team):
 
Using the data set from T-60 to T+243 sec from recent telemetry downlinks,
we report further analysis of BAT GRB 131103A (trigger #576562)
(Cummings, et al., GCN Circ. 15440).  The BAT ground-calculated position is
RA, Dec = 348.948, -44.645 deg which is 
   RA(J2000)  =  23h 15m 47.5s 
   Dec(J2000) = -44d 38' 42.3" 
with an uncertainty of 1.8 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 30%.
 
The mask-weighted light curve shows a 2 or 3 overlapping peaks starting
at ~T-8 sec, peaking at ~T+0 sec, and ending at ~T+15 sec.
T90 (15-350 keV) is 17.3 +- 4.8 sec (estimated error including systematics).
 
The time-averaged spectrum from T-9.5 to T+13.5 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.97 +- 0.19.  The fluence in the 15-150 keV band is 8.2 +- 1.0 x 10^-7 erg/cm2.
The 1-sec peak photon flux measured from T+0.62 sec in the 15-150 keV band
is 1.5 +- 0.3 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/576562/BA/