{
  "bibcode": "2011GCN.12581....1C",
  "body": "J. R. Cummings (GSFC/UMBC), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC),\nV. D'Elia (ASDC), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA),\nC. B. Markwardt (GSFC), J. Norris (BSU), D. M. Palmer (LANL), T. Sakamoto (GSFC/UMBC),\nM. Stamatikos (OSU), J. Tueller (GSFC), T. N. Ukwatta (MSU)\n(i.e. the Swift-BAT team):\n \nUsing the data set from T-60 to T+243 sec from recent telemetry downlinks,\nwe report further analysis of BAT GRB 111121A (trigger #508161)\n(D'Elia, et al., GCN Circ. 12578).  The BAT ground-calculated position is\nRA, Dec = 154.746, -46.670 deg, which is \n   RA(J2000)  =  10h 18m 59.1s \n   Dec(J2000) = -46d 40' 10.7\" \nwith an uncertainty of 1.1 arcmin, (radius, sys+stat, 90% containment).\nThe partial coding was 64%.\n \nThe mask-weighted light curve shows an inital strong pulse composed \nof two overlapping peaks, the first starting at ~T-0.3 sec and \npeaking at ~T+0.17 sec (at 2.6 cnts/det/sec). The second peaks\nat ~T+0.3 sec and is done by ~T+0.6 sec.  This is followed by\ntwo episodes of extended emission.  The first is roughly constant\n(~0.02 to 0.03 cnts/det/sec) out to ~T+65sec.  The second episode\nis ~0.006 cnts/det/sec out to ~T+130 sec.  T90 (15-350 keV)\nis 119 +- 16 sec (estimated error including systematics).\nThis T90 includes the extended emission.\n\nThe spectral lag is 10.2 ms +2.6-1.8 ms (for the 100-350 to 25-50 keV band)\nand 12.7 ms +6.8-8.7 ms (for the 50-100 to 15-25 keV band).  This puts it\non the long end of the distribution for spectral lag for short GRBs.\n \nThe time-averaged spectrum from T-0.34 to T+141.08 sec is best fit by a simple\npower-law model.  The power law index of the time-averaged spectrum is\n1.66 +- 0.12.  The fluence in the 15-150 keV band is 2.2 +- 0.2 x 10^-6 erg/cm2.\nThe 1-sec peak photon flux measured from T-0.26 sec in the 15-150 keV band\nis 7.1 +- 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\nhttp://gcn.gsfc.nasa.gov/notices_s/508161/BA/",
  "circularId": 12581,
  "createdOn": 1321924503000,
  "email": "scott@lheamail.gsfc.nasa.gov",
  "subject": "GRB 111121A: Swift-BAT refined analysis",
  "submitter": "Scott Barthelmy at NASA/GSFC  <scott@lheamail.gsfc.nasa.gov>",
  "eventId": "GRB 111121A"
}