{
  "bibcode": "2025GCN.41730....1P",
  "createdOn": 1757107702058,
  "submittedHow": "web",
  "eventId": "GRB 250904A",
  "format": "text/plain",
  "subject": "GRB 250904A: Swift-BAT refined analysis",
  "body": "D. M. Palmer (LANL), 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),\nT. Parsotan (GSFC), D. Sadaula (GSFC/UMBC),\nT. Sakamoto (AGU) (i.e. the Swift-BAT team):\n \nUsing the data set from T-239 to T+963 sec from the recent telemetry downlink,\nwe report further analysis of BAT GRB 250904 A (trigger #1347179)\n(Salvaggio, et al., GCN Circ. 41704).  The BAT ground-calculated position is\nRA, Dec = 84.377, 3.575 deg which is \n   RA(J2000)  =  05h 37m 30.5s \n   Dec(J2000) = +03d 34' 29.9\" \nwith an uncertainty of 1.0 arcmin (radius, sys+stat, 90% containment).\nThe partial coding was 100%.\n \nThe BAT light curve showed a complex structure with a duration of about 50 sec.\nT90 (15-350 keV) is 37.11 +- 13.89 sec (estimated error including systematics).\n \nThe time-averaged spectrum from T-19.68 to T+54.44 sec is best fit by a simple\npower-law model.  The power law index of the time-averaged spectrum is\n1.40 +- 0.11.  The fluence in the 15-150 keV band is 1.7 +- 0.1 x 10^-06 erg/cm2.\nThe 1-sec peak photon flux measured from T+5.11 sec in the 15-150 keV band\nis 1.1 +- 0.2 ph/cm2/sec.  All the quoted errors are at the 90% confidence level. \n \nThe results of the batgrbproduct analysis are available at\nhttps://swift.gsfc.nasa.gov/results/batgrbcat/BAT_refined_circular/1347179\n",
  "circularId": 41730,
  "submitter": "D. R. Sadaula at NASA GSFC <dev.r.sadaula@nasa.gov>"
}