GCN Circular 26286
Subject
GRB 191123A: Swift-BAT refined analysis
Date
2019-11-23T22:52:53Z (4 years ago)
From
Hans Krimm at NSF/NASA-GSFC <hkrimm@nsf.gov>
S. Laha (GSFC/UMBC), S. D. Barthelmy (GSFC), J. R. Cummings (CPI),
H. A. Krimm (NSF), A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC),
D. M. Palmer (LANL), T. Sakamoto (AGU), M. Stamatikos (OSU),
A. Tohuvavohu (U Toronto), T. N. Ukwatta (LANL) (i.e. the Swift-BAT team):
Using the data set from T-239 to T+963 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 191123A (trigger #939079)
(Tohuvavohu, et al., GCN Circ. 26279). The BAT ground-calculated position is
RA, Dec = 215.289, 22.823 deg which is
RA(J2000) = 14h 21m 09.3s
Dec(J2000) = +22d 49' 23.5"
with an uncertainty of 2.2 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 85%.
The mask-weighted light curve shows a pair of pulses, each with some sub-
structure. The first starts at ~T-10 sec, peaks at T+0 and decays by T+40 sec.
The second pulse starts at T+110 sec, peaks soon afterward and decays by
T+180 sec. T90 (15-350 keV) is 275.1 +- 102.4 sec (estimated error including
systematics).
The time-averaged spectrum from -2.1 to 288.1 sec is best fit by a simple
power-law model. The power law index of the time-averaged spectrum is
1.67 +- 0.25. The fluence in the 15-150 keV band is 1.2 +- 0.2 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+111.77 sec in the 15-150 keV band
is 1.2 +- 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/939079/BA/