{
  "subject": "GRB 250225B: Swift-BAT refined analysis",
  "bibcode": "2025GCN.39668....1S",
  "createdOn": 1741716356379,
  "eventId": "GRB 250225B",
  "body": "T. Sakamoto (AGU), S. D. Barthelmy (GSFC),\nR. Gupta (GSFC), H. A. Krimm (NSF),\nS. Laha (GSFC/UMBC), A. Y. Lien (U Tampa),\nC. B. Markwardt (GSFC), M. J. Moss (GSFC),\nD. M. Palmer (LANL), T. Parsotan (GSFC),\nD. Sadaula (GSFC/UMBC), M. A. Williams (PSU)\n(i.e. the Swift-BAT team):\n\nUsing the data set from T-240 to T+160 sec from the recent telemetry downlink,\nwe report further analysis of BAT GRB 250225B (trigger #1291459)\n(Williams et al., GCN Circ. 39473).  The BAT ground-calculated position is\nRA, Dec = 306.134, -41.481 deg which is\n   RA(J2000)  =  20h 24m 32.2s\n   Dec(J2000) = -41d 28' 50.8\"\nwith an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).\nThe partial coding was 47%.\n\nThe mask-weighted BAT light curve shows a bright peak around the trigger time, followed by multiple fainter peaks. After approximately 160 seconds, the GRB was no longer in the BAT field of view (FOV).\nT90 (15-350 keV) is 110.46 +- 2.12 sec (estimated error including systematics).\n\nThe time-averaged spectrum from T-0.02 to T+122.46 sec is best fit by a simple\npower-law model.  The power law index of the time-averaged spectrum is\n1.60 +- 0.07.  The fluence in the 15-150 keV band is 6.5 +- 0.2 x 10^-06 erg/cm2.\nThe 1-sec peak photon flux measured from T+1.31 sec in the 15-150 keV band\nis 10.4 +- 0.5 ph/cm2/sec.  All the quoted errors are at the 90% confidence\nlevel.\n \nThe results of the batgrbproduct analysis are available at\nhttps://swift.gsfc.nasa.gov/results/batgrbcat/BAT_refined_circular/1291459\n ",
  "submitter": "Rahul Gupta at NASA GSFC <rahul.gupta@nasa.gov>",
  "submittedHow": "web",
  "format": "text/plain",
  "circularId": 39668
}