GCN Circular 15063

GRB 130803A, Swift-BAT refined analysis
  
J. R. Cummings (GSFC/UMBC), S. D. Barthelmy (GSFC),  W. H. Baumgartner (GSFC/UMBC),
E. E. Fenimore (LANL), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA),
A. Y. Lien (NASA/GSFC/ORAU), C. B. Markwardt (GSFC), K. L. Page (U Leicester),
D. M. Palmer (LANL), T. Sakamoto (AGU), G. Sato (ISAS), 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 the recent telemetry downlink,
we report further analysis of BAT GRB 130803A (trigger #565263) (Page, et al.,
GCN Circ. 15059
Not found
 
 
).  The BAT ground-calculated position is
RA, Dec = 220.256, -2.499 deg which is
    RA(J2000)  =  14h 41m 01.4s
    Dec(J2000) = -02d 29' 58"
with an uncertainty of 1.1 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 30%.
  
The mask-weighted light curve shows two well-separated symmetrical peaks.  The
first, larger peak starts at about T0-2 seconds and lasts until about T+8 seconds.
The second peak, which was softer, starts about T0+41 seconds and lasts until about
T0+48 seconds.  T90 (15-350 keV) is 44 +- 2 sec (estimated error including
systematics).
  
The time-averaged spectrum from T-1.24 to T+45.76 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.69 +- 0.14.  The fluence in the 15-150 keV band is 1.5 +- 0.1 x 10^-06 erg/cm2.
The 1-sec peak photon flux measured from T+2.09 sec in the 15-150 keV band
is 5.1 +- 0.4 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/565263/BA/