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GCN Circular 35385

Subject
GRB 231214A: Swift-BAT refined analysis
Date
2023-12-17T04:55:15Z (10 months ago)
From
Takanori Sakamoto at AGU <tsakamoto@phys.aoyama.ac.jp>
Via
legacy email
M. Stamatikos (OSU), S. D. Barthelmy (GSFC), R. Brivio (INAF-OAB),
H. A. Krimm (NSF), S. Laha (GSFC/UMBC), A. Y. Lien (U Tampa),
C. B. Markwardt (GSFC), M. Moss (GSFC), D. M. Palmer (LANL),
T. Parsotan (GSFC/UMBC), T. Sakamoto (AGU)
(i.e. the Swift-BAT team):
 Using the data set from T-35 to T+962 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 231214A (trigger #1202386)
(Brivio, et al., GCN Circ. 35335).  The BAT ground-calculated position is
RA, Dec = 305.666, -72.432 deg which is
   RA(J2000)  =  20h 22m 39.7s
   Dec(J2000) = -72d 25' 54.3"
with an uncertainty of 1.1 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 39%.
 The mask-weighted light curve shows two bright overlapping peaks.  The first
peak starts from T-5 s, peaks at T+1 s and ends at T+10 s.  The second peak
starts from T+10 s, peaks at T+12 s and ends at T+25 s.
T90 (15-350 keV) is 27.8 +- 7.3 sec (estimated error including systematics).
 The time-averaged spectrum from T-5.37 to T+49.42 sec is best fit by a power law
with an exponential cutoff.  This fit gives a photon index 0.87 +- 0.23,
and Epeak of 167 +- 94 keV (chi squared 60.53 for 56 d.o.f.).  For this
model the total fluence in the 15-150 keV band is 9.6 +- 0.3 x 10^-6 erg/cm2
and the 1-sec peak flux measured from T+12.57 sec in the 15-150 keV band is
11.3 +- 0.6 ph/cm2/sec.  A fit to a simple power law gives a photon index
of 1.25 +- 0.05 (chi squared 69.34 for 57 d.o.f.).  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/1202386/BA/


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