{
  "subject": "GRB 160804A: Swift-BAT refined analysis",
  "eventId": "GRB 160804A",
  "bibcode": "2016GCN.19765....1K",
  "createdOn": 1470313867000,
  "circularId": 19765,
  "submitter": "Scott Barthelmy at NASA/GSFC  <scott@lheamail.gsfc.nasa.gov>",
  "email": "scott@lheamail.gsfc.nasa.gov",
  "body": "H. A. Krimm (GSFC/USRA), S. D. Barthelmy (GSFC), J. R. Cummings (GSFC/UMBC),\nN. Gehrels (GSFC), A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC),\nF. E. Marshall (NASA/GSFC), D. M. Palmer (LANL), T. Sakamoto (AGU),\nM. Stamatikos (OSU), T. N. Ukwatta (LANL)\n(i.e. the Swift-BAT team):\n \nUsing the data set from T-239 to T+963 sec from recent telemetry downlinks,\nwe report further analysis of BAT GRB 160804A (trigger #707231)\n(Marshall, et al., GCN Circ. 19761).  The BAT ground-calculated position is\nRA, Dec = 221.652, 10.002 deg, which is \n   RA(J2000)  =  14h 46m 36.4s \n   Dec(J2000) = +10d 00' 06.2\" \nwith an uncertainty of 1.3 arcmin, (radius, sys+stat, 90% containment).\nThe partial coding was 28%.\n \nThe mask-weighted light curve shost several overlapping peaks starting\nat ~T+20sec (possibly at ~T-30 sec), peaking at ~T+90 sec, and returning\nto baseline at ~T+330 sec.  T90 (15-350 keV) is 144.2 +- 19.2 sec\n(estimated error including systematics).\n \nThe time-averaged spectrum from T+25.14 to T+247.15 sec is best fit by a power law\nwith an exponential cutoff.  This fit gives a photon index 1.40 +- 0.23, \nand Epeak of 52.7 +- 5.4 keV (chi squared 57.0 for 56 d.o.f.).  For this\nmodel the total fluence in the 15-150 keV band is 1.14 +- 0.03 x 10^-5 erg/cm2\nand the 1-sec peak flux measured from T+88.59 sec in the 15-150 keV band is\n2.9 +- 0.3 ph/cm2/sec.  A fit to a simple power law gives a photon index\nof 1.99 +- 0.05 (chi squared 79.05 for 57 d.o.f.).  All the quoted errors\nare at the 90% confidence level. \n \nThe results of the batgrbproduct analysis are available at\nhttp://gcn.gsfc.nasa.gov/notices_s/707231/BA/"
}