Back

GCN Circular 12524

Subject

GRB 111103B: Swift-BAT refined analysis

Date

2011-11-03T15:45:44Z (13 years ago)

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), D. Grupe (PSU), H. A. Krimm (GSFC/USRA),
C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (GSFC/UMBC),
M. Stamatikos (OSU), J. Tueller (GSFC), T. N. Ukwatta (MSU)
(i.e. the Swift-BAT team):
 
Using the data set from T-239 to T+418 sec from recent telemetry downlinks,
we report further analysis of BAT GRB 111103B (trigger #506903)
(Grupe, et al., GCN Circ. 12519Loading...
 
 ).  The BAT ground-calculated position is
RA, Dec = 265.691, 1.605 deg which is 
   RA(J2000)  =  17h 42m 45.8s 
   Dec(J2000) = +01d 36' 19.4" 
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 90%.
 
The mask-weighted light curve shows at least 4 overlapping peaks in the first
group: starting at ~T-25 sec, with the brightest peak at ~T+8 sec, and ending
at ~T+90 sec.  The second group of peaks starts at ~T+100 sec and ends
at ~T+250 sec.  T90 (15-350 keV) is 167 +- 35 sec (estimated error
including systematics).
 
The time-averaged spectrum from T-6.55 to T+250.78 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.41 +- 0.05.  The fluence in the 15-150 keV band is 8.0 +- 0.2 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+5.48 sec in the 15-150 keV band
is 7.2 +- 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/506903/BA/