{
  "bibcode": "2021GCN.29632....1M",
  "body": "C. B. Markwardt (GSFC), E. Ambrosi (INAF-IASFPA), S. D. Barthelmy (GSFC),\nJ. R. Cummings (CPI), H. A. Krimm (NSF), S. Laha (GSFC/UMBC),\nA. Y. Lien (GSFC/UMBC), D. M. Palmer (LANL), T. Sakamoto (AGU),\nM. Stamatikos (OSU), T. N. Ukwatta (LANL)\n(i.e. the Swift-BAT team):\n  \nUsing the data set from T-239 to T+700 sec from the recent telemetry downlink,\nwe report further analysis of BAT GRB 210307A (trigger #1036139)\n(Ambrosi, et al., GCN Circ. 29610).  The BAT ground-calculated position is\nRA, Dec = 119.244, -66.965 deg which is\n    RA(J2000)  =  07h 56m 58.5s\n    Dec(J2000) = -66d 57' 54.3\"\nwith an uncertainty of 2.1 arcmin, (radius, sys+stat, 90% containment).\nThe partial coding was 79%.\n  \nThe mask-weighted light curve shows two isolated peaks.  The initial peak starts\nat T-30 sec, peaks at T0 and ends at T+40 sec.  The second peak starts at\nT+110 sec, peaks at T+118 sec and ends at T+150 sec.  T90 (15-350 keV) is\n262 +- 83 sec (estimated error including systematics).\n\nThe time-averaged spectrum from T-159.61 to T+174.53 sec is best fit by a simple\npower-law model.  The power law index of the time-averaged spectrum is\n1.56 +- 0.16.  The fluence in the 15-150 keV band is 2.8 +- 0.3 x 10^-6 erg/cm2.\nThe 1-sec peak photon flux measured from T+1.27 sec in the 15-150 keV band\nis 1.0 +- 0.2 ph/cm2/sec.  All the quoted errors are at the 90% confidence\nlevel.\n\nThe results of the batgrbproduct analysis are available at\nhttp://gcn.gsfc.nasa.gov/notices_s/1036139/BA/",
  "circularId": 29632,
  "createdOn": 1615259278000,
  "email": "tsakamoto@phys.aoyama.ac.jp",
  "subject": "GRB 210307A: Swift-BAT refined analysis",
  "submitter": "Takanori Sakamoto at AGU  <tsakamoto@phys.aoyama.ac.jp>",
  "eventId": "GRB 210307A"
}