GCN Circular 11295
Subject
GRB 100924A: Swift-BAT refined analysis
Date
2010-09-25T03:03:08Z (14 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), H. A. Krimm (GSFC/USRA), V. Mangano (INAF-IASFPA),
C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (GSFC/UMBC),
M. Stamatikos (OSU), J. Tueller (GSFC), T. N. Ukwatta (GWU)
(i.e. the Swift-BAT team):
Using the data set from T-239 to T+963 sec from recent telemetry downlinks,
we report further analysis of BAT GRB 100924A (trigger #434843)
(Mangano, et al., GCN Circ. 11294). The BAT ground-calculated position is
RA, Dec = 0.672, 7.004 deg which is
RA(J2000) = 00h 02m 41.3s
Dec(J2000) = +07d 00' 15.0"
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 25%.
The mask-weighted light curve shows an initial cluster of two peaks starting
at ~T-4 sec, peaking at ~T_zero, and returning to essentially background at ~T+20 sec.
The second cluster has approximately 8 peakis starting at ~T+20 sec, with
main peaks at ~T+35, +45, +52, +60, amd +68, and returning to background
around T+120 sec. T90 (15-350 keV) is 96.0 +- 16.0 sec (estimated error
including systematics).
The time-averaged spectrum from T-15.1 to T+128.9 sec is best fit by a simple
power-law model. The power law index of the time-averaged spectrum is
1.53 +- 0.06. The fluence in the 15-150 keV band is 8.3 +- 0.3 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+56.40 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/434843/BA/