GCN Circular 40852
Subject
GRB 250625A: Swift-BAT refined analysis
Event
Date
2025-06-27T23:16:03Z (19 hours ago)
From
Amy <yarleen@gmail.com>
Via
email
A. Y. Lien (U Tampa), S. D. Barthelmy (GSFC), M. Ferro (INAF-OAB), R. Gupta
(GSFC), H. A. Krimm (NSF), S. Laha (GSFC/UMBC), 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+100 sec from the recent telemetry
downlink, we report further analysis of BAT GRB 250625A (trigger #1327910)
(Ferro et al., GCN Circ. 40825). The BAT ground-calculated position is
RA, Dec = 261.517, 22.245 deg which is
RA(J2000) = 17h 26m 04.1s
Dec(J2000) = +22d 14' 40.7"
with an uncertainty of 1.9 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 68%.
The mask-weighted light curve shows a single-pulse structure that starts at
~T0, peaks at ~T+2 s, and ends at ~T+6 s. T90 (15-350 keV) is 4.00 +- 1.41
sec (estimated error including systematics).
The time-averaged spectrum from T-0.35 to T+3.65 sec is best fit by a
simple power-law model. The power law index of the time-averaged spectrum
is 1.00 +- 0.22. The fluence in the 15-150 keV band is 2.8 +- 0.4 x 10^-07
erg/cm2. The 1-sec peak photon flux measured from T+1.65 sec in the 15-150
keV band is 0.8 +- 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/1327910