TITLE: GCN CIRCULAR NUMBER: 42876 SUBJECT: GRB 251126A: Swift-BAT refined analysis DATE: 25/11/29 01:05:23 GMT FROM: Amy <yarleen@gmail.com> S. D. Barthelmy (GSFC), R. Caputo (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), 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 251126A (trigger #1417793) (Caputo et al., GCN Circ. 42843). The BAT ground-calculated position is RA, Dec = 99.939, 54.989 deg which is RA(J2000) = 06h 39m 45.4s Dec(J2000) = +54d 59' 21.9" with an uncertainty of 1.3 arcmin, (radius, sys+stat, 90% containment). The partial coding was 96%. The mask-weighted light curve shows two overlapping pulses. The first pulse peaks at ~T+1 s, and the second pulse peaks at ~T+4 s. The overall structure starts at ~T0 and ends at ~T+10 s. T90 (15-350 keV) is 9.00 +- 2.00 sec (estimated error including systematics). The time-averaged spectrum from T-0.41 to T+10.59 sec is best fit by a power law with an exponential cutoff. This fit gives a photon index 0.43 +- 0.71, and Epeak of 51.4 +- 8.8 keV (chi squared 58.43 for 56 d.o.f.). For this model the total fluence in the 15-150 keV band is 4.4 +- 0.4 x 10^-07 erg/cm2 and the 1-sec peak flux measured from T+0.59 sec in the 15-150 keV band is 1.3 +- 0.2 ph/cm2/sec. A fit to a simple power law gives a photon index of 1.76 +- 0.12 (chi squared 72.99 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/1417793 View this GCN Circular online at https://gcn.nasa.gov/circulars/42876. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...