{
  "bibcode": "2006GCN..5029....1S",
  "body": "T. Sakamoto (NASA/ORAU), L. Barbier (GSFC), S. Barthelmy (GSFC),\nS. Campana (INAF-OAB), J. Cummings (NASA/ORAU), E. Fenimore (LANL),\nN. Gehrels (GSFC), D. Hullinger (BYU-Idaho), H. Krimm (GSFC/USRA),\nC. Markwardt (GSFC/UMD), D. Palmer (LANL), A. Parsons (GSFC),\nG. Sato (ISAS), J. Tueller (GSFC), M. Koss (UMD), M. Stamatikos (NASA/ORAU)\non behalf of 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 060428B (trigger #207399)\n(Campana, et al., GCN 5017).  The BAT ground-calculated position is RA,Dec =\n235.378,+62.027 deg {15h 41m 30.8s,+62d 1' 35.8\"} (J2000) +- 1.7 arcmin,\n(radius, sys+stat, 90% containment).  The partial coding was 74%.\n \nThe mask-weighted lightcurve shows a broad peak starting at T-20 sec\nuntil ~T+44 sec.  T90 (15-350 keV) is 58 +- 3 sec (estimated error\nincluding systematics).\n \nThe time-averaged spectrum from T-23.8 to T+41.9 is best fit by a power law\nwith an exponential cutoff.  This fit gives a photon index 0.94 +- 1.30, \nand Epeak of 21.7 +- 14.0 keV (chi squared 68.81 for 56 d.o.f.).  \nFor this model the total fluence in the 15-150 keV band is\n7.2 +- 0.9 x 10^-7 erg/cm2 and the 1-sec peak flux measured from T+20.78 sec\nin the 15-150 keV band is 0.6 +- 0.1 ph/cm2/sec.  A fit to a simple power law\ngives a photon index of 2.58 +- 0.19 (chi squared 75.57 for 57 d.o.f.).\nAll the quoted errors are at the 90% confidence level.",
  "circularId": 5029,
  "createdOn": 1146249676000,
  "email": "Scott@lheamail.gsfc.nasa.gov",
  "subject": "GRB 060428B:  Refined analysis of the Swift-BAT burst",
  "submitter": "Scott Barthelmy at NASA/GSFC  <Scott@lheamail.gsfc.nasa.gov>",
  "eventId": "GRB 060428B"
}