{
  "circularId": 42058,
  "submitter": "Mike Moss at NASA GSFC <mikejmoss3@gmail.com>",
  "createdOn": 1759435801664,
  "eventId": "GRB 251001B",
  "subject": "GRB 251001B: Swift-BAT refined analysis",
  "bibcode": "2025GCN.42058....1K",
  "submittedHow": "web",
  "body": "H. A. Krimm (NSF), S. D. Barthelmy (GSFC), \nA. P. Beardmore (U Leicester), R. Gupta (GSFC),\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), T. Sakamoto (AGU)\n(i.e. the Swift-BAT team):\n \nUsing the data set from T-240 to T+962 sec from the recent telemetry downlink,\nwe report further analysis of BAT GRB 251001B (trigger #1400467)\n(Beardmore, et al., GCN Circ. 42039).  The BAT ground-calculated position is\nRA, Dec = 42.668, -22.990 deg which is \n   RA(J2000)  =  02h 50m 40.2s \n   Dec(J2000) = -22d 59' 23.9\" \nwith an uncertainty of 1.1 arcmin, (radius, sys+stat, 90% containment).\nThe partial coding was 91%.\n \nThe mask-weighted light curve shows a single FRED pulse from ~T0-5 s to ~T0+20 s.\nStatistically significant emission is found to occur out to ~T0+90 s.  \nThe T90 (15-350 keV) is 75.33 +- 46.90 sec (estimated error including systematics).\n \nThe time-averaged spectrum from T-9.98 to T+91.72 sec is best fit by a simple\npower-law model.  The power law index of the time-averaged spectrum is\n1.49 +- 0.14.  The fluence in the 15-150 keV band is 1.1 +- 0.1 x 10^-06 erg/cm2.\nThe 1-sec peak photon flux measured from T+2.29 sec in the 15-150 keV band\nis 0.8 +- 0.1 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/1400467",
  "format": "text/plain"
}