{
  "bibcode": "2012GCN.12817....1D",
  "body": "P. D'Avanzo (INAF-OAB), V. D'Elia (ASDC), V. Mangano (INAF-IASFPA),\nJ.A. Kennea (PSU), M.C. Stroh (PSU), D.N. Burrows (PSU), J.P. Osborne\n(U. Leicester), K.L. Page (U. Leicester), C. Pagani (U. Leicester) and\nS. Immler report on behalf of the Swift-XRT team:\n\nWe have analysed 12 ks of XRT data for GRB 120106A (Immler  et al. GCN\nCirc. 12810), from 64 s to 29.5 ks after the  BAT trigger. The data\ncomprise 273 s in Windowed Timing (WT) mode (the first 8 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 Evans et\nal. (GCN. Circ 12813).\n\nThe light curve can be modelled with an initial power-law decay with an\nindex of alpha=4.3 (+/-0.3), followed by a break at T+152 s to an alpha\nof 0.91 (+0.05, -0.04).\n\nA spectrum formed from the PC mode data can be fitted with an absorbed\npower-law with a photon spectral index of 2.15 (+0.12, -0.15). The\nbest-fitting absorption column is  7.6 (+6.8, -0.7) x 10^21 cm^-2,\nconsistent with the Galactic value of 7.0 x 10^21 cm^-2 (Kalberla et\nal. 2005). The counts to observed (unabsorbed) 0.3-10 keV flux\nconversion factor deduced from this spectrum  is 4.8 x 10^-11 (1.0 x\n10^-10) erg cm^-2 count^-1. \n\nA summary of the PC-mode spectrum is thus:\nTotal column:\t     7.6 (+6.8, -0.7) x 10^21 cm^-2\nGalactic foreground: 7.0 x 10^21 cm^-2\nExcess significance: <1.6 sigma\nPhoton index:\t     2.15 (+0.12, -0.15)\n\nThe results of the XRT-team automatic analysis are available at\nhttp://www.swift.ac.uk/xrt_products/00511235.\n\nThis circular is an official product of the Swift-XRT team.",
  "circularId": 12817,
  "createdOn": 1325903163000,
  "email": "pae9@star.le.ac.uk",
  "subject": "GRB 120106A: Swift-XRT refined Analysis",
  "submitter": "Phil Evans at U of Leicester  <pae9@star.le.ac.uk>",
  "eventId": "GRB 120106A"
}