{
  "bibcode": "2012GCN.12952....1K",
  "body": "J.A. Kennea (PSU), M.C. Stroh (PSU), D.N. Burrows (PSU), A.P. Beardmore\n(U. Leicester), P.A. Evans (U. Leicester), O.M. Littlejohns (U.\nLeicester), A. Melandri (INAF-OAB), B. Sbarufatti (INAF-OAB/PSU), G.\nStratta (ASDC) and T. Sakamoto report on behalf of the Swift-XRT team:\n\nWe have analysed 6.5 ks of XRT data for GRB 120213A (Sakamoto  et al.\nGCN Circ. 12942), from 53 s to 22.8 ks after the  BAT trigger. The data\ncomprise 886 s in Windowed Timing (WT) mode with the remainder in\nPhoton Counting (PC) mode. The enhanced XRT position for this burst was\ngiven by Beardmore et al. (GCN. Circ 12944).\n\nThe late-time light curve (from T0+5.3 ks) can be modelled with  a\npower-law decay with a decay index of alpha=3.02 (+0.19, -0.18).\n\nA spectrum formed from the WT mode data can be fitted with an absorbed\npower-law with a photon spectral index\tof 3.28 (+/-0.07). The\nbest-fitting absorption column is  3.52 (+0.15, -0.14) x 10^21 cm^-2,\nin excess of the Galactic value of 1.0 x 10^21 cm^-2 (Kalberla et al.\n2005). The PC mode spectrum has a photon index of 2.22 (+/-0.15) and a\nbest-fitting absorption column of 1.7 (+/-0.4) x 10^21 cm^-2. The\ncounts to observed (unabsorbed) 0.3-10 keV flux conversion factor\ndeduced from this spectrum  is 3.4 x 10^-11 (5.4 x 10^-11) erg cm^-2\ncount^-1. \n\nA summary of the PC-mode spectrum is thus:\nTotal column:\t     1.7 (+/-0.4) x 10^21 cm^-2\nGalactic foreground: 1.0 x 10^21 cm^-2\nExcess significance: 3.2 sigma\nPhoton index:\t     2.22 (+/-0.15)\n\nThe results of the XRT-team automatic analysis are available at\nhttp://www.swift.ac.uk/xrt_products/00514767.\n\nThis circular is an official product of the Swift-XRT team.",
  "circularId": 12952,
  "createdOn": 1329136803000,
  "email": "pae9@star.le.ac.uk",
  "subject": "GRB 120213A: Swift-XRT refined Analysis",
  "submitter": "Phil Evans at U of Leicester  <pae9@star.le.ac.uk>",
  "eventId": "GRB 120213A"
}