{
  "bibcode": "2009GCN..9749....1U",
  "body": "T. N. Ukwatta (GWU), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC),\nJ. K. Cannizzo (GSFC/UMBC), J. R. Cummings (GSFC/UMBC), E. E. Fenimore (LANL),\nN. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC/UMD),\nD. M. Palmer (LANL), A. M. Parsons (GSFC), T. Sakamoto (GSFC/UMBC),\nG. Sato (ISAS), M. Stamatikos (GSFC/ORAU), J. Tueller (GSFC),\n(i.e. the Swift-BAT team):\n\nUsing the data set from T-239 to T+423 sec from the recent telemetry downlink,\nwe report further analysis of BAT GRB 090807 (trigger #359378)\n(Cannizzo, et al., GCN Circ. 9746).  The BAT ground-calculated position is\nRA, Dec = 273.741, 10.279 deg which is\n   RA(J2000)  =  18h 14m 57.8s\n   Dec(J2000) = +10d 16' 45.9\"\nwith an uncertainty of 1.8 arcmin, (radius, sys+stat, 90% containment).\nThe partial coding was 64%.\n\nThe mask-weighted light curve shows a complex structure lasting from\nT-5 to T+150 seconds with at least five peaks superimposed on a broad,\nsoft and slowly varying background.  There is an additional peak at\nT+185 sec which corresponds to a large flare seen in the Swift/XRT.\nThere is also possible precursor activity from T-200 to T-80 sec.\nT90 (15-350 keV) is 140.8 +- 13.1 sec (estimated error including\nsystematics).\n\nThe time-averaged spectrum from T-9.5 to T+151.5 sec is best fit by a simple\npower-law model.  The power law index of the time-averaged spectrum is\n2.25 +- 0.14.  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+41.96 sec in the 15-150 keV band\nis 0.7 +- 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/359378/BA/",
  "circularId": 9749,
  "createdOn": 1249675571000,
  "email": "hans.krimm@nasa.gov",
  "subject": "GRB 090807, Swift-BAT refined analysis",
  "submitter": "Hans Krimm at NASA-GSFC  <hans.krimm@nasa.gov>",
  "eventId": "GRB 090807"
}