{
  "bibcode": "2010GCN.10505....1S",
  "body": "R.L.C. Starling, P.A. Evans (U. Leicester) and M. Stamatikos (OSU/NASA/GSFC) \nreport on behalf of the Swift-XRT team:\n\nWe have analysed the first orbit of Swift XRT data for GRB 100316D (Stamatikos \net al. GCN Circ. 10496), comprising 593 s of exposure\nfrom 143 s to 737 s after the BAT trigger. The data are solely in\nWindowed Timing (WT) mode. The light curve over this time decays very \nslowly and can be modelled with a power-law with a decay index of\nalpha=0.13+/-0.03.\n\nA spectrum formed from these data can be fitted with an absorbed power-law with \na photon spectral index of 1.42 (+/-0.04). The best-fitting absorption column \nis 5.9 (+/-0.3) x 10^21 cm^-2, in excess of the Galactic value of 7.0 x 10^20 \ncm^-2 (Kalberla et al. 2005). The counts to observed (unabsorbed) 0.3-10 \nkeV flux conversion factor deduced from this spectrum is 6.6 x 10^-11 \n(8.7 x 10^-11) erg cm^-2 count^-1.\n\nIf the decay contines with alpha=0.13, the predicted count rate at T+24h \nis 16 count s^-1 or an observed (unabsorbed) 0.3-10 keV flux of 1.1 (1.4) \nx10^-9 erg cm-2 s-1.\n\nThe results of the XRT-team automatic analysis are available at \nhttp://www.swift.ac.uk/xrt_products/00416135.\n\nThis circular is an official product of the Swift-XRT team.",
  "circularId": 10505,
  "createdOn": 1268764379000,
  "email": "rlcs1@star.le.ac.uk",
  "subject": "GRB 100316D: Swift XRT refined analysis",
  "submitter": "Rhaana Starling at U of Leicester  <rlcs1@star.le.ac.uk>",
  "eventId": "GRB 100316D"
}