TITLE: GCN CIRCULAR NUMBER: 42444 SUBJECT: GRB 251024A: Swift-BAT refined analysis DATE: 25/10/25 19:40:31 GMT FROM: Amy yarleen@gmail.com
T. Sakamoto (AGU), S. D. Barthelmy (GSFC), R. Gupta (GSFC), H. A. Krimm (NSF), S. Laha (GSFC/UMBC), A. Y. Lien (U Tampa), C. B. Markwardt (GSFC), M. J. Moss (GSFC), D. M. Palmer (LANL), T. Parsotan (GSFC), D. Sadaula (GSFC/UMBC) (i.e. the Swift-BAT team):
Using the data set from T-240 to T+613 sec from the recent telemetry downlink, we report further analysis of BAT GRB 251024A (trigger #1406589) (Moss et al., GCN Circ. 42426). The BAT ground-calculated position is RA, Dec = 306.666, -68.576 deg which is RA(J2000) = 20h 26m 39.7s Dec(J2000) = -68d 34' 34.3" with an uncertainty of 2.4 arcmin, (radius, sys+stat, 90% containment). The partial coding was 84%.
The mask-weighted light curve shows a weak pulse structure that starts at ~T+1 s and peaks at ~T+3 s. The main pulse structure ends at ~T+25 s, and there are some tail emissions that last till ~T+100 s. T90 (15-350 keV) is 82.66 +- 23.27 sec (estimated error including systematics).
The time-averaged spectrum from T+1.16 to T+97.28 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.68 +- 0.30. The fluence in the 15-150 keV band is 6.5 +- 1.2 x 10^-07 erg/cm2. The 1-sec peak photon flux measured from T+2.16 sec in the 15-150 keV band is 0.5 +- 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/1406589
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