{
  "bibcode": "2011GCN.11679....1D",
  "body": "V. D'Elia (ASDC) reports on behalf of the Swift-XRT team:\n\nWe have analysed 20 ks of XRT data for GRB 110208A (D'Elia  et al. GCN\nCirc. 11674), from 64 s to 47.3 ks after the  BAT trigger. The data\ncomprise 55 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 Evans et\nal. (GCN. Circ 11678).\n\nThe late-time light curve (from T0+4.3 ks) can be modelled with  a\npower-law decay with a decay index of alpha=1.21 (+0.20, -0.18).\n\nA spectrum formed from the PC mode data can be fitted with an absorbed\npower-law with a photon spectral index of 2.27 (+/-0.25). The\nbest-fitting absorption column is  1.1 (+0.4, -0.6) x 10^21 cm^-2, in\nexcess of the Galactic value of 2.3 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 3.3 x 10^-11 (4.7 x 10^-11) erg\ncm^-2 count^-1. \n\nA summary of the PC-mode spectrum is thus:\nTotal column:\t     1.1 (+0.4, -0.6) x 10^21 cm^-2\nGalactic foreground: 2.3 x 10^20 cm^-2\nExcess significance: 3.2 sigma\nPhoton index:\t     2.27 (+/-0.25)\n\nThe results of the XRT-team automatic analysis are available at\nhttp://www.swift.ac.uk/xrt_products/00445038.\n\nThis circular is an official product of the Swift-XRT team.",
  "circularId": 11679,
  "createdOn": 1297262568000,
  "email": "delia@asdc.asi.it",
  "subject": "GRB 110208A: Swift-XRT refined Analysis",
  "submitter": "Valerio D'Elia at ASDC  <delia@asdc.asi.it>",
  "eventId": "GRB 110208A"
}