GCN Circular 23500
Subject
GRB 181203A: Swift-BAT refined analysis
Date
2018-12-04T03:52:49Z (5 years ago)
From
Amy Lien at GSFC <amy.y.lien@nasa.gov>
S. D. Barthelmy (GSFC), J. R. Cummings (CPI),
H. A. Krimm (NSF/USRA), A. Y. Lien (GSFC/UMBC),
C. B. Markwardt (GSFC), D. M. Palmer (LANL),
T. Sakamoto (AGU), M. Stamatikos (OSU),
E. Troja (NASA/GSFC/UMCP), T. N. Ukwatta (LANL)
(i.e. the Swift-BAT team):
Using the data set from T-240 to T+962 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 181203A (trigger #874475)
(Troja et al., GCN Circ. 23493). The BAT ground-calculated position is
RA, Dec = 108.341, -39.783 deg which is
RA(J2000) = 07h 13m 21.8s
Dec(J2000) = -39d 46' 57.1"
with an uncertainty of 1.3 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 83%.
The mask-weighted light curve shows a single-peaked structure that starts at
~T-2 s, peaks at ~T+1 s, and ends at ~T+16 s. T90 (15-350 keV) is 15.30 +- 1.75 sec
(estimated error including systematics).
The time-averaged spectrum from T-1.96 to T+15.77 sec is best fit by a simple
power-law model. The power law index of the time-averaged spectrum is
1.79 +- 0.15. The fluence in the 15-150 keV band is 7.8 +- 0.7 x 10^-7 erg/cm2.
The 1-sec peak photon flux measured from T+1.02 sec in the 15-150 keV band
is 1.1 +- 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/874475/BA/