{
  "bibcode": "2013GCN.14317....1P",
  "body": "K.L. Page (U. Leicester), C. Pagani (U. Leicester), G. Stratta (ASDC),\nP. D'Avanzo (INAF-OAB), V. D'Elia (ASDC), M.C. Stroh (PSU), D.N.\nBurrows (PSU), J.A. Kennea (PSU), A.P. Beardmore (U. Leicester) and\nP.A. Evans report on behalf of the Swift-XRT team:\n\nWe have analysed 10 ks of XRT data for GRB 130315A (Evans  et al. GCN\nCirc. 14311),  from 167 s to 29.4 ks after the\tBAT trigger. The data\ncomprise 337 s in Windowed Timing (WT) mode with the remainder in\nPhoton Counting (PC) mode. The refined XRT position is RA, Dec =\n157.54687, -51.79362 which is equivalent to:\n\nRA (J2000): 10 30 11.25\nDec(J2000): -51 47 37.0\n\nwith an uncertainty of 3.6 arcsec (radius, 90% confidence).\n\nThe light curve can be modelled with  a power-law decay with a decay\nindex of alpha=.\n\nA spectrum formed from the WT mode data can be fitted with an absorbed\npower-law with a photon spectral index\tof 1.49 (+/-0.04). The\nbest-fitting absorption column is  2.88 (+0.19, -0.18) x 10^21 cm^-2,\nin excess of the Galactic value of 2.3 x 10^21 cm^-2 (Kalberla et al.\n2005). The PC mode spectrum has a photon index of 2.1 (+/-0.3) and a\nbest-fitting absorption column of 3.1 (+1.2, -0.8) x 10^21 cm^-2. The\ncounts to observed (unabsorbed) 0.3-10 keV flux conversion factor\ndeduced from this spectrum  is 3.9 x 10^-11 (6.7 x 10^-11) erg cm^-2\ncount^-1. \n\nA summary of the PC-mode spectrum is thus:\nTotal column:\t     3.1 (+1.2, -0.8) x 10^21 cm^-2\nGalactic foreground: 2.3 x 10^21 cm^-2\nExcess significance: <1.6 sigma\nPhoton index:\t     2.1 (+/-0.3)\n\nThe results of the XRT-team automatic analysis are available at\nhttp://www.swift.ac.uk/xrt_products/00551126.\n\nThis circular is an official product of the Swift-XRT team.",
  "circularId": 14317,
  "createdOn": 1363395545000,
  "email": "pae9@leicester.ac.uk",
  "subject": "GRB 130315A: Swift-XRT refined Analysis",
  "submitter": "Phil Evans at U of Leicester  <pae9@leicester.ac.uk>",
  "eventId": "GRB 130315A"
}