{
  "format": "text/plain",
  "submitter": "Takanori Sakamoto at AGU <tsakamoto@phys.aoyama.ac.jp>",
  "circularId": 40765,
  "submittedHow": "web",
  "bibcode": "2025GCN.40765....1B",
  "createdOn": 1750214935658,
  "eventId": "GRB 250615A",
  "subject": "GRB 250615A: Swift-BAT refined analysis",
  "body": "S. D. Barthelmy (GSFC), S. Dichiara (PSU), R. Gupta (GSFC),\nH. A. Krimm (NSF), S. Laha (GSFC/UMBC), A. Y. Lien (U Tampa),\nC. B. Markwardt (GSFC), M. J. Moss (GSFC), D. M. Palmer (LANL),\nT. Parsotan (GSFC), D. Sadaula (GSFC/UMBC), T. Sakamoto (AGU)\n(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 250615A (trigger #1324646)\n(Dichiara, et al., GCN Circ. 40736).  The BAT ground-calculated position is\nRA, Dec = 290.384, 4.679 deg which is\n   RA(J2000)  =  19h 21m 32.1s\n   Dec(J2000) = +04d 40' 44.0\"\nwith an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).\nThe partial coding was 56%.\n\nThe mask-weighted light curve shows a complex structure that\nstarts at T-5 sec, peaks at T+5 sec, and ends at T+77 sec.\nT90 (15-350 keV) is 52.5 +- 10.3 sec (estimated error including systematics).\n\nThe time-averaged spectrum from -5.2 to 77.3 sec is best fit by a simple\npower-law model.  The power law index of the time-averaged spectrum is\n1.22 +- 0.08.  The fluence in the 15-150 keV band is 3.8 +- 0.2 x 10^-6 erg/cm2.\nThe 1-sec peak photon flux measured from T+3.29 sec in the 15-150 keV band\nis 4.1 +- 0.3 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/1324646"
}