{
  "bibcode": "2012GCN.13041....1U",
  "body": "T. N. Ukwatta (MSU), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC),\nJ. R. Cummings (GSFC/UMBC), E. E. Fenimore (LANL), N. Gehrels (GSFC),\nH. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC), F. E. Marshall (NASA/GSFC),\nD. M. Palmer (LANL), T. Sakamoto (GSFC/UMBC), G. Sato (ISAS),\nM. Stamatikos (OSU), J. Tueller (GSFC)\n(i.e. the Swift-BAT team):\n \nUsing the data set from T-120 to T+258 sec from recent telemetry downlinks,\nwe report further analysis of BAT GRB 120311B (trigger #517489)\n(Marshall, et al., GCN Circ. 13038).  The BAT ground-calculated position is\nRA, Dec = 258.551, -13.068 deg, which is \n   RA(J2000)  =  17h 14m 12.2s \n   Dec(J2000) = -13d 04' 05.0\" \nwith an uncertainty of 1.3 arcmin, (radius, sys+stat, 90% containment).\nThe partial coding was 62%.\n \nThe mask-weighted light curve shows two nearly separated peaks, the first\nstarting at ~T-15 sec, peaking at ~T_0,  and the minimum between the two\npeaks is at ~T+5 sec. The second peak peaks at ~T+10 sec, and\nreturns to baseline at ~T+22 sec.  T90 (15-350 keV) is 28.2 +- 5.5 sec\n(estimated error including systematics).\n \nThe time-averaged spectrum from T-13.88 to T+21.63 sec is best fit by a simple\npower-law model.  The power law index of the time-averaged spectrum is\n1.96 +- 0.14.  The fluence in the 15-150 keV band is 1.0 +- 0.1 x 10^-6 erg/cm2.\nThe 1-sec peak photon flux measured from T+9.04 sec in the 15-150 keV band\nis 1.5 +- 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/517489/BA/",
  "circularId": 13041,
  "createdOn": 1331501485000,
  "email": "scott@lheamail.gsfc.nasa.gov",
  "subject": "GRB 120311B: Swift-BAT refined analysis",
  "submitter": "Scott Barthelmy at NASA/GSFC  <scott@lheamail.gsfc.nasa.gov>",
  "eventId": "GRB 120311B"
}