{
  "bibcode": "2005GCN..3105....1K",
  "body": "H. Krimm (GSFC/USRA), S. Barthelmy, L. Barbier (GSFC), J. Cummings (GSFC/NRC),\nE. Fenimore (LANL), R. Fink, N. Gehrels (GSFC), S.T. Holland (GSFC/USRA),\nD. Hullinger (GSFC/UMD), K. Hurley (UCB), H. Krimm (GSFC/USRA),\nC. Markwardt (GSFC/UMD), D. Palmer (LANL), A. Parsons (GSFC),\nS. Piranomonte (ASDC), T. Sakamoto (GSFC/NRC), G. Sato (ISAS),\nA. Smale (NASA HQ), M. Suzuki (Saitama), J. Tueller (GSFC)\non behalf of the Swift-BAT team:\n\nContinued analysis of the full data set (now with telemetry gaps \nfilled in) for the Swift-BAT GRB050315 (Parsons et al., GCN Circ \n3094, Sakamoto et al., GCN Circ 3099) yields a fluence of 4.2 x 10^-6 \nerg/cm2 in the 15-350 keV band and a peak flux of 2.4 ph/cm2/sec \n(also 15-350 keV). The photon index of the 1-s peak spectrum (T0+24.6 \nsec.) is 2.4 +- 0.3 (90% confidence).  The time averaged spectrum \nalso shows a soft spectrum with a power law index of 2.3 +- 0.1 (90% \nconfidence).   The Swift mission is still in its early orbit phase \nand the BAT spectral response continues to be refined.  Further \nspectral analysis is in progress.  In particular, since there is an \nuncertainty in the energy response at the lowest energies at the \ncurrent time, it is not possible to conclude that this event is an \nX-ray flash.\n\nThe burst shows considerable structure in its light curve.  There is \na precursor starting ~60 seconds before the trigger and continuing up \nuntil the main peak emission begins. The first of the two main peaks \nhas a slow rise of about ten seconds and a gradual decline \ninterrupted at TO ~22 seconds by a second peak with a much steeper \nrise.  The burst shows signs of spectral evolution (hard to soft) \nfrom the precursor through the two main peaks. There is no \nsignificant emission after the decay of the second peak.  The overall \nmeasures of burst duration give T90 = 96 +- 10 seconds and T50 = 25 \n+- 5 seconds.  The errors in duration are estimated systematic errors.",
  "circularId": 3105,
  "createdOn": 1111012905000,
  "email": "krimm@milkyway.gsfc.nasa.gov",
  "subject": "GRB 050315: Swift-BAT further refined analysis",
  "submitter": "Hans Krimm at NASA-GSFC  <krimm@milkyway.gsfc.nasa.gov>",
  "eventId": "GRB 050315"
}