{
  "bibcode": "2005GCN..3938....1S",
  "body": "T. Sakamoto (GSFC/NRC), L. Barbier (GSFC), S. Barthelmy (GSFC),\nJ. Cummings (GSFC/NRC), D. Hullinger (GSFC/UMD), E. Fenimore (LANL), \nN. Gehrels (GSFC), H. Krimm (GSFC/USRA), C. Markwardt (GSFC/UMD), \nD. Palmer (LANL), A. Parsons (GSFC), G. Sato (ISAS), J. Tueller (GSFC)\non behalf of the Swift-BAT team:\n\nWe now have the complete BAT data for GRB 050904 (Cummings et al.,\nGCN circ. 3910 and Palmer et al. GCN circ. 3918).  This was a very\nlong, bright burst.  The light curve shows 3 main peaks.  There are \n15-second long peaks at ~T+28 sec and ~T+56 sec, and the main peak \nwas from ~T+80 sec to ~T+220 sec, along with weaker peaks.  Emission \nin the BAT energy range continues to almost T+500 sec with a weak \npeak at ~T+470 sec.  T90 was 225 +/- 10 sec (estimated error including \nsystematics, 15-350 keV).\n\nFitting a simple power law from T+17 sec to T+226 sec, the photon\nindex is 1.34 +/- 0.06.  The fluence is 5.4 +/- 0.2 x 10^6 ergs/cm^2.\nThe 1-second peak flux from T+27.5 sec is 0.8 +- 0.2 photons/cm^2/sec.\nAll errors are 90% confidence, energy range 15-150 keV.\n\nHaislip et al. (GNC circ. 3914, 3919) reported a Ly-alpha break for \nthis burst corresponding to a redshift of 5.3 to 9.0.  Antonelli et al. \n(GCN circ. 3924) calculate a redshift of 6.1.  Kawai et al. (GCN circ.\n3937) report a spectrographic redshift of 6.29. With the above fluence \nat this redshift (6.29), the isotropic energy equivalent is \n3.8 x 10^53 ergs in the range 109 - 1094 keV in the GRB rest frame.",
  "circularId": 3938,
  "createdOn": 1126119304000,
  "email": "jayc@milkyway.gsfc.nasa.gov",
  "subject": "GRB 050904 BAT refined analysis of complete data set",
  "submitter": "Jay R. Cummings at NASA/GSFC/Swift  <jayc@milkyway.gsfc.nasa.gov>",
  "eventId": "GRB 050904"
}