[vsnet-grb-info 9411] GRB 100625A: Swift-BAT refined analysis

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  10891
SUBJECT: GRB 100625A: Swift-BAT refined analysis
DATE:    10/06/26 14:34:54 GMT
FROM:    Michael Stamatikos at OSU/GSFC  <michael.stamatikos-1 at nasa.gov>

S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), J. R. Cummings (GSFC/UMBC), 
E. E. Fenimore (LANL), N. Gehrels (GSFC), S. T. Holland (CRESST/USRA/GSFC), 
H. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC/UMD), D. M. Palmer (LANL), 
A. M. Parsons (GSFC), T. Sakamoto (GSFC/UMBC), G. Sato (ISAS), 
M. Stamatikos (OSU/NASA/GSFC), J. Tueller (GSFC), T. N. Ukwatta (GWU) 
(i.e. the Swift-BAT team):
 
Using the data set from T-239 to T+500 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 100625A (trigger #425647)
(Holland, et al., GCN Circ. 10884).  The BAT ground-calculated position is
RA, Dec = 15.796, -39.091 deg which is 
   RA(J2000)  =  01h 03m 11.1s 
   Dec(J2000) = -39d 05' 29.3" 
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 100%.
 
The mask-weighted light curve shows two overlapping peaks starting at ~T-0.1 sec,
peaking at ~T+0.1 and T+0.2 sec, and ending at ~T+0.3 sec.  There is a weak soft
tail out to ~T+30 sec.  T90 (15-350 keV) is 0.33 +- 0.03 sec (estimated error
including systematics).
 
The time-averaged spectrum from T-0.1 to T+0.3 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
0.90 +- 0.10.  The fluence in the 15-150 keV band is 2.3 +- 0.2 x 10^-07 erg/cm2.
The 1-sec peak photon flux measured from T-0.37 sec in the 15-150 keV band
is 2.6 +- 0.2 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/425647/BA/