{
  "bibcode": "2015GCN.18086....1S",
  "body": "M. Stamatikos (OSU), S. D. Barthelmy (GSFC), S. B. Cenko (GSFC),\nJ. R. Cummings (GSFC/UMBC), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA),\nA. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC), D. M. Palmer (LANL),\nT. Sakamoto (AGU), T. N. Ukwatta (LANL)\n(i.e. the Swift-BAT team):\n \nUsing the data set from T-239 to T+963 sec from the recent telemetry downlinks,\nwe report further analysis of BAT GRB 150727A (trigger #650530)\n(Cenko, et al., GCN Circ. 18076).  The BAT ground-calculated position is\nRA, Dec = 203.968, -18.320 deg, which is \n   RA(J2000)  =  13h 35m 52.3s \n   Dec(J2000) = -18d 19' 11.4\" \nwith an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).\nThe partial coding was 68%.\n \nThe mask-weighted light curve shows a FRED-like peak starting at ~T-8 sec,\npeaking at ~T+5 sec, and ramping down to a flat level at ~T+80 sec.\nThere is a second, small peak at ~T+90 sec.  The low level emission\ncontinues (with a weak decline) out to T+870 sec when observations stop\ndue to an observing constraint.\nT90 (15-350 keV) is 88 +- 13 sec (estimated error including systematics).\n \nThe time-averaged spectrum from T-8.70 to T+95.94 sec is best fit by a simple\npower-law model.  The power law index of the time-averaged spectrum is\n1.14 +- 0.07.  The fluence in the 15-150 keV band is 3.7 +- 0.2 x 10^-6 erg/cm2.\nThe 1-sec peak photon flux measured from T+9.21 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/650530/BA/\n\n[GCN OPS NOTE(29jul15): Per author's request, the typo on the uncertainty\nin the T90 value was changed from 133 to 13 sec.]",
  "circularId": 18086,
  "createdOn": 1438085152000,
  "email": "scott@lheamail.gsfc.nasa.gov",
  "subject": "GRB 150727A: Swift-BAT refined analysis",
  "submitter": "Scott Barthelmy at NASA/GSFC  <scott@lheamail.gsfc.nasa.gov>",
  "eventId": "GRB 150727A"
}