{
  "bibcode": "2007GCN..6158....1B",
  "body": "L. Barbier (GSFC), S. D. Barthelmy (GSFC), J. Cummings (GSFC/UMBC),\nE. Fenimore (LANL), N. Gehrels (GSFC), H. Krimm (GSFC/USRA),\nC. Markwardt (GSFC/UMD), C. Pagani (PSU), D. Palmer (LANL),\nA. Parsons (GSFC), T. Sakamoto (GSFC/ORAU), G. Sato (GSFC/ISAS),\nM. Stamatikos (GSFC/ORAU), J. Tueller (GSFC)\non behalf of the Swift-BAT team:\n \nUsing the data set from T-2.0 to T+8.1 sec, we report further analysis \nof BAT GRB 070227 (trigger #262347)  (Pagani, et al., GCN Circ. 6156).  \nThe BAT ground-calculated position is RA, Dec = 120.566, -46.305 (J2000)\n  RA:  +08h 02m 16s\n  Dec: -46d 18' 17\"\nwith an uncertainty of 2.5 arcmin, (radius, sys+stat, 90% containment).  \nThe partial coding was 3%.  Because this was a failed trigger on-board, \nthis is all the detailed BAT data we are going to get on this burst.\n \nThe burst had two weak overlapping peaks with spectral evolution. The\nlarger peak was at T+1 and the smaller at T+6 sec.  There is no \nadditional strong emission at times later than T+8, but we cannot rule \nout weak emission.  T90 (15-350 keV) is 7 +- 2 sec (estimated error \nincluding systematics).\n \nThe time-averaged spectrum from T+0.0 to T+8.0 is best fit by a simple \npower-law model.  The power law index of the time-averaged spectrum is \n1.54 +- 0.27.  The fluence in the 15-150 keV band is \n1.6 +- 0.2 x 10^-06 erg/cm2.  The 1-sec peak photon flux measured from \nT+0.00 sec in the 15-150 keV band is 2.7 +- 0.4 ph/cm2/sec.  The quoted \nerrors are at the 90% confidence level considering the statistical and\nusual systematic effects.  However, because of the extreme partial coding\nof this burst, and particularly the reduced sensitivity to low energy\nphotons at the edge of the FOV, we expect an extra systematic uncertainty\ncontribution of about 10%.",
  "circularId": 6158,
  "createdOn": 1172697642000,
  "email": "jayc@milkyway.gsfc.nasa.gov",
  "subject": "GRB 070227, Swift-BAT refined analysis",
  "submitter": "Jay R. Cummings at NASA/GSFC/Swift  <jayc@milkyway.gsfc.nasa.gov>",
  "eventId": "GRB 070227"
}