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GCN Circular 29297

Subject
GRB 210112A: Swift-BAT refined analysis
Date
2021-01-13T01:45:13Z (4 years ago)
From
Amy Lien at GSFC <amy.y.lien@nasa.gov>
M. Stamatikos (OSU), E. Ambrosi (INAF-IASFPA),
S. D. Barthelmy (GSFC), H. A. Krimm (NSF),
S. Laha (GSFC/UMBC), A. Y. Lien (GSFC/UMBC),
C. B. Markwardt (GSFC), D. M. Palmer (LANL),
T. Sakamoto (AGU), 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 210112A (trigger #1016881)
(Ambrosi et al., GCN Circ. 29289Loading...
 
 ).  The BAT ground-calculated position is
RA, Dec = 219.005, 33.058 deg which is
   RA(J2000)  =  14h 36m 01.3s
   Dec(J2000) = +33d 03' 30.4"
with an uncertainty of 1.2 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 89%.

The mask-weighted light curve shows a multi-peaked structure that starts
at ~T-10 s and ends at ~T+220 s. The three main peaks occur at ~T+1 s,
~T+70 s, and ~T+105 s, respectively, and the one at ~T+70 s is the largest
peak.
T90 (15-350 keV) is 107.60 +- 13.02 sec (estimated error including
systematics).

The time-averaged spectrum from T-10.44 to T+218.47 sec is best fit by
a simple power-law model.  The power law index of the time-averaged
spectrum  is 1.45 +- 0.03.  The fluence in the 15-150 keV band is
2.33 +- 0.03 x 10^-5 erg/cm2. The 1-sec peak photon flux measured from
T+68.86 sec in the 15-150 keV band is 20.5 +- 0.6 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/1016881/BA/