{
  "bibcode": "2008GCN..7462....1C",
  "body": "J. Cummings (GSFC/UMBC), S. D. Barthelmy (GSFC), E. Fenimore (LANL),\nN. Gehrels (GSFC), H. Krimm (GSFC/USRA), C. Markwardt (GSFC/UMD),\nK. McLean (GSFC/UMD), D. Palmer (LANL), A. Parsons (GSFC),\nJ. L. Racusin (PSU), T. Sakamoto (GSFC/UMBC), G. Sato (GSFC/ISAS),\nM. Stamatikos (GSFC/ORAU), J. Tueller (GSFC), T. Ukwatta (GWU)\n(i.e. the Swift-BAT team):\n \nUsing the data set from T-120 to T+182 sec from recent telemetry downlinks,\nwe report further analysis of BAT GRB 080319B (trigger #306757)\n(Racusin, et al., GCN Circ. 7427).  The BAT ground-calculated position is\nRA, Dec = 217.919, 36.300 deg which is \n   RA(J2000)  =  14h 31m 40.7s \n   Dec(J2000) = +36d 17' 58.4\" \nwith an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).\nThe partial coding was 100%.\n \nThe mask-weighted light curve shows a large long bump of a peak\nstarting at ~T-10 sec, ramping up until ~T+10 sec, then mostly a flat top\nwith some small structure superposed, then starting to decay at ~T+50 sec.\nIt returns nearly to background by ~T+64 sec at which point there is\na loss of data due to an on-board data product buffer overflow.\nThe data resumes at T+120 sec.  There is still detectable emission\nin the BAT 15-350 keV band out to T+180 sec (the limit of the data\ndownlinked so far).  From other count rate data products, we can say\nthat there is no other peaks during the 60-sec missing event data window\nand that the low-level emission is about 10-15% of the peak emission.\nGiven the missing data, T90 (15-350 keV) has to be >50 sec\n(estimated error including systematics).\n \nThe time-averaged spectrum from T-3.8 to T+62.2 and T+120 to T+151 sec\nis fit by a simple power-law model.  The power law index\nof the time-averaged spectrum is 1.04 +- 0.02.  The fluence\nin the 15-150 keV band is 8.1 +- 0.1 x 10^-05 erg/cm2.\nThe 1-sec peak photon flux measured from T+16.87 sec in the 15-150 keV band\nis 24.8 +- 0.5 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/306757/BA/\n\nDue to a large backlog in downlinking the full data on this burst,\nwe currently do not have the usual data set out to long times yet.\nShould the remaining data show that there is ongoing activity \nfor this burst past the data cutoff at T+182sec, then we will\nissue an updated 'refined analysis' circular.",
  "circularId": 7462,
  "createdOn": 1205958104000,
  "email": "scott@lheamail.gsfc.nasa.gov",
  "subject": "GRB 080319B, Swift-BAT refined analysis",
  "submitter": "Scott Barthelmy at NASA/GSFC  <scott@lheamail.gsfc.nasa.gov>",
  "eventId": "GRB 080319B"
}