{
  "bibcode": "2011GCN.12509....1L",
  "body": "O. M. Littlejohns (U. Leicester) and E. Troja (NASA/GSFC/ORAU) report\non behalf of the Swift-XRT team:\n\nWe have analysed 19 ks of XRT data for GRB 111029A (Troja  et al. GCN\nCirc. 12498), from 163 s to 58.0 ks after the  BAT trigger. The data\ncomprise 25 s in Windowed Timing (WT) mode with the remainder in Photon\nCounting (PC) mode. The enhanced XRT position for this burst was given\nby Evans et al. (GCN. Circ 12502).\n\nThe light curve can be modelled with  a power-law decay with a decay\nindex of alpha=1.06 (+0.07, -0.08).\n\nA spectrum formed from the PC mode data can be fitted with an absorbed\npower-law with a photon spectral index of 2.6 (+0.7, -0.5). The\nbest-fitting absorption column is  1.5 (+0.6, -0.3) x 10^22 cm^-2, in\nexcess of the Galactic value of 6.3 x 10^21 cm^-2 (Kalberla et al.\n2005). The counts to observed (unabsorbed) 0.3-10 keV flux conversion\nfactor deduced from this spectrum  is 5.0 x 10^-11 (2.1 x 10^-10) erg\ncm^-2 count^-1. \n\nA summary of the PC-mode spectrum is thus:\nTotal column:\t     1.5 (+0.6, -0.3) x 10^22 cm^-2\nGalactic foreground: 6.3 x 10^21 cm^-2\nExcess significance: 3.9 sigma\nPhoton index:\t     2.6 (+0.7, -0.5)\n\nThe results of the XRT-team automatic analysis are available at\nhttp://www.swift.ac.uk/xrt_products/00506519.\n\nThis circular is an official product of the Swift-XRT team.",
  "circularId": 12509,
  "createdOn": 1319969003000,
  "email": "oml2@le.ac.uk",
  "subject": "GRB 111029A: Swift-XRT refined Analysis",
  "submitter": "Owen Littlejohns at U of Leicester  <oml2@le.ac.uk>",
  "eventId": "GRB 111029A"
}