{
  "bibcode": "2012GCN.13416....1O",
  "body": "J.P. Osborne (U. Leicester), K.L. Page (U. Leicester), C. Pagani (U.\nLeicester), A. Melandri (INAF-OAB), B. Sbarufatti (INAF-OAB/PSU), G.\nStratta (ASDC), J.A. Kennea (PSU), M.C. Stroh (PSU), D.N. Burrows (PSU)\nand B.-B. Zhang report on behalf of the Swift-XRT team:\n\nWe have analysed 12 ks of XRT data for GRB 120703A (-B. Zhang  et al.\nGCN Circ. 13408), from 70 s to 68.9 ks after the  BAT trigger. The data\ncomprise 374 s in Windowed Timing (WT) mode (the first 9 s were taken\nwhile Swift was slewing) with the remainder in Photon Counting (PC)\nmode. The enhanced XRT position for this burst was given by Goad et al.\n(GCN. Circ 13415).\n\nThe light curve can be modelled with an initial power-law decay with an\nindex of alpha=0.69 (+0.04, -0.06), followed by a break at T+4130 s to\nan alpha of 1.04 (+/-0.06).\n\nA spectrum formed from the PC mode data can be fitted with an absorbed\npower-law with a photon spectral index of 2.00 (+0.13, -0.12). The\nbest-fitting absorption column is  1.4 (+/-0.3) x 10^21 cm^-2, in\nexcess of the Galactic value of 1.2 x 10^20 cm^-2 (Kalberla et al.\n2005). The counts to observed (unabsorbed) 0.3-10 keV flux conversion\nfactor deduced from this spectrum  is 3.7 x 10^-11 (5.1 x 10^-11) erg\ncm^-2 count^-1. \n\nA summary of the PC-mode spectrum is thus:\nTotal column:\t     1.4 (+/-0.3) x 10^21 cm^-2\nGalactic foreground: 1.2 x 10^20 cm^-2\nExcess significance: 7.0 sigma\nPhoton index:\t     2.00 (+0.13, -0.12)\n\nThe results of the XRT-team automatic analysis are available at\nhttp://www.swift.ac.uk/xrt_products/00525671.\n\nThis circular is an official product of the Swift-XRT team.",
  "circularId": 13416,
  "createdOn": 1341444844000,
  "email": "pae9@star.le.ac.uk",
  "subject": "GRB 120703A: Swift-XRT refined Analysis",
  "submitter": "Phil Evans at U of Leicester  <pae9@star.le.ac.uk>",
  "eventId": "GRB 120703A"
}