GCN Circular 43129

Subject

GRB 251214B: Swift-BAT refined analysis

Event

GRB 251214B

Date

2025-12-15T16:41:36Z (20 hours ago)

From

Rahul Gupta at NASA GSFC <rahul.gupta@nasa.gov>

Via

Web form

S. Laha (GSFC/UMBC), S. D. Barthelmy (GSFC), 
R. A. J. Eyles-Ferris (U Leicester), R. Gupta (GSFC),
H. A. Krimm (NSF), A. Y. Lien (U Tampa),
C. B. Markwardt (GSFC), M. J. Moss (GSFC),
D. M. Palmer (LANL), T. Parsotan (GSFC),
D. Sadaula (GSFC/UMBC), T. Sakamoto (AGU)
(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 251214B (trigger #1423875)
(Eyles-Ferris, et al., GCN Circ. 43089Loading...
 
 ).  The BAT ground-calculated position is
RA, Dec = 330.222, -9.155 deg which is 
   RA(J2000)  =  22h 00m 53.4s 
   Dec(J2000) = -09d 09' 17.3" 
with an uncertainty of 1.2 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 99%.
 
The mask-weighted BAT light curve shows a double-peaked structure with a duration of about 10 sec
T90 (15-350 keV) is 9.38 +- 0.73 sec (estimated error including systematics).
 
The time-averaged spectrum from T-0.19 to T+9.97 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.79 +- 0.12.  The fluence in the 15-150 keV band is 5.0 +- 0.4 x 10^-07 erg/cm2.
The 1-sec peak photon flux measured from T-0.13 sec in the 15-150 keV band
is 2.0 +- 0.2 ph/cm2/sec.  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/1423875