{
  "bibcode": "2010GCN.10511....1S",
  "body": "T. Sakamoto (GSFC/UMBC), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC),\nJ. R. Cummings (GSFC/UMBC), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA),\nC. B. Markwardt (GSFC/UMD), D. M. Palmer (LANL), M. Stamatikos (GSFC/ORAU),\nJ. Tueller (GSFC), T. N. Ukwatta (GWU)\n(i.e. the Swift-BAT team):\n \nUsing the data set from T-60 to T+243 sec from the telemetry downlinks,\nwe report further analysis of BAT GRB 100316D (trigger #416135)\n(Stamatikos, et al., GCN Circ. 10496).  The BAT ground-calculated position is\nRA, Dec = 107.599, -56.275 deg, which is \n   RA(J2000)  =  07h 10m 23.8s \n   Dec(J2000) = -56d 16' 28.9\" \nwith an uncertainty of 3.0 arcmin, (radius, sys+stat, 90% containment).\nThe partial coding was 85%.\n \nThe mask-weighted light curve is relatively flat.  The emission started\nbefore T-80 sec when the location came into the BAT FoV during a\nSwift planned-target slew.  Using the event-by-event data, the lightcurve\nconitinue through the 64-sec integration of the image trigger and out to\nat least T+240 sec.  Using the on-board mask-weighted lightcurve,\nthe lightcurve continues out to at least T+740 sec where the data ends.\n \nThe time-averaged spectrum using just the T+0.0 to T+64.0 sec image-trigger\ninterval is best fit by a simple power-law model.  The power law index of the\ntime-averaged spectrum is 2.29 +- 0.41.  The fluence in the 15-150 keV band\nis 3.0 +- 0.8 x 10^-7 erg/cm2.  The 1-sec peak photon flux measured\nfrom T+0.00 sec in the 15-150 keV band is 0.1 +- 0.0 ph/cm2/sec.\nAll the quoted errors are at the 90% confidence level. \n \nThe results of the batgrbproduct analysis are available at\nhttp://gcn.gsfc.nasa.gov/notices_s/416135/BA/\n\nWe note that this lightcurve is very non-typical for a GRB and that\nthe spectrum is soft.  This is similar both in the temporal and spectral\nproperties to the GRB060218-SN2006aj burst (Camapana, et al.; Nature,\nv224, p1008, Figure 1).  In the 060218 burst, the BAT lightcurve was flat\nfrom T-50 to T+300 sec.  The X-ray temporal decay (Starling, GCN Circ 10505)\nis shallow as it was in SN2006aj (Campana, Fig 1).  We further note\nthat the 5 arcsec XRT error circle (GCN 10496) covers the edge\nof an extended object (a pair of unresolved stars or a galaxy) in DSS.",
  "circularId": 10511,
  "createdOn": 1268781392000,
  "email": "scott@lheamail.gsfc.nasa.gov",
  "subject": "GRB 100316D: Swift-BAT refined analysis",
  "submitter": "Scott Barthelmy at NASA/GSFC  <scott@lheamail.gsfc.nasa.gov>",
  "eventId": "GRB 100316D"
}