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GCN Circular 42686

Subject
GRB 251112A: Swift-BAT refined analysis
Date
2025-11-14T20:37:19Z (4 days ago)
From
Rahul Gupta at NASA GSFC <rahul.gupta@nasa.gov>
Via
Web form
D. Sadaula (GSFC/UMBC), S. D. Barthelmy (GSFC), 
R. Gupta (GSFC), H. A. Krimm (NSF),
S. Laha (GSFC/UMBC), A. Y. Lien (U Tampa),
C. B. Markwardt (GSFC), A. Mei (INAF-OAB)
M. J. Moss (GSFC), D. M. Palmer (LANL),
T. Parsotan (GSFC), T. Sakamoto (AGU)
(i.e. the Swift-BAT team):
 
Using the data set from T-240 to T+963 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 251112A (trigger #1413695)
(Mei, et al., GCN Circ. 42656).  The BAT ground-calculated position is
RA, Dec = 274.081, 24.158 deg which is 
   RA(J2000)  =  18h 16m 19.5s 
   Dec(J2000) = +24d 09' 28.8" 
with an uncertainty of 1.4 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 100%.
 
The mask-weighted BAT light curve shows multi-peaked emission starting ~T-28 sec.
T90 (15-350 keV) is 55.42 +- 6.65 sec (estimated error including systematics).
 
The time-averaged spectrum from T-28.30 to T+32.38 sec is best fit by a power law
with an exponential cutoff.  This fit gives a photon index 0.77 +- 0.75, 
and Epeak of 48.4 +- 11.9 keV (chi squared 86.37 for 56 d.o.f.).  For this
model the total fluence in the 15-150 keV band is 7.6 +- 0.9 x 10^-07 erg/cm2
and the 1-sec peak flux measured from T+1.05 sec in the 15-150 keV band is
0.7 +- 0.1 ph/cm2/sec.  A fit to a simple power law gives a photon index
of 1.86 +- 0.15 (chi squared 94.39 for 57 d.o.f.).  All the quoted errors
are at the 90% confidence level. 
 
The results of the batgrbproduct analysis are available at
https://swift.gsfc.nasa.gov/results/batgrbcat/BAT_refined_circular/1413695
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