{
  "bibcode": "2013GCN.14300....1O",
  "body": "J.P. Osborne (U. Leicester), K.L. Page (U. Leicester), C. Pagani (U.\nLeicester), B. Sbarufatti (INAF-OAB/PSU), G. Stratta (ASDC), P.\nD'Avanzo (INAF-OAB), J.A. Kennea (PSU), M.C. Stroh (PSU), D.N. Burrows\n(PSU) and B.P. Gompertz report on behalf of the Swift-XRT team:\n\nWe have analysed 9.1 ks of XRT data for GRB 130313A (Gompertz  et al.\nGCN Circ. 14293),  from 85 s to 18.7 ks after the  BAT trigger. The\ndata are entirely in Photon Counting (PC) mode. The refined XRT\nposition is RA, Dec = 236.41004, -0.36897 which is equivalent to:\n\nRA (J2000): 15 45 38.41\nDec(J2000): -00 22 08.3\n\nwith an uncertainty of 4.8 arcsec (radius, 90% confidence). We cannot\ndetermine at the present time whether the source is fading.\n\nA spectrum formed from the PC mode data can be fitted with an absorbed\npower-law with a photon spectral index of 1.6 (+3.4, -4.0). The\nbest-fitting absorption column is  consistent with the Galactic value\nof 5.9 x 10^20 cm^-2 (Kalberla et al. 2005). The counts to observed\n(unabsorbed) 0.3-10 keV flux conversion factor deduced from this\nspectrum  is 7.0 x 10^-11 (7.8 x 10^-11) erg cm^-2 count^-1. \n\nA summary of the PC-mode spectrum is thus:\nTotal column:\t     0 (+1.7, -0) x 10^23 cm^-2\nGalactic foreground: 5.9 x 10^20 cm^-2\nExcess significance: <1.6 sigma\nPhoton index:\t     1.6 (+3.4, -4.0)\n\nThe results of the XRT-team automatic analysis are available at\nhttp://www.swift.ac.uk/xrt_products/00550906.\n\nThis circular is an official product of the Swift-XRT team.",
  "circularId": 14300,
  "createdOn": 1363235224000,
  "email": "pae9@leicester.ac.uk",
  "subject": "GRB 130313A: Swift-XRT refined Analysis",
  "submitter": "Phil Evans at U of Leicester  <pae9@leicester.ac.uk>",
  "eventId": "GRB 130313A"
}