{
  "bibcode": "2008GCN..8031....1E",
  "body": "P.A. Evans (U. Leicester) and S. Immler (CRESST/GSFC/UMD) report\non behalf of the Swift-XRT team:\n\nWe have analysed 1.6 ks of XRT data for GRB 080727B (Immler et al., GCN\nCirc 8022). The data were taken in two snapshots; the first started 105\ns after the trigger and contained 51 s of Windowed Timing mode data\nfollowed by 500 s of Photon Counting (PC) mode data. The second snapshot\nbegan at T0+11 ks, and contained 1.2 ks of data, all in PC mode.\n\nThe UVOT-enhanced XRT position has been given by Goad et al. (GCN Circ.\n8026).\n\nThe light curve shows an initial steep decay with a power-law index of\n2.47 (+1.38, -0.39), with a break to a shallower decay of 1.05 (+0.20,\n-0.13). The break occurred at T0+267 (+89, -100) s.\n\nA spectrum formed from all available PC mode data can be modelled by an\nabsorbed power law with a photon index on 1.61 (+0.43, -0.38). The best\nfitting absorption column is 8.7 (+4.1, -2.9) x 10^21 cm^-2, in excess\nof the Galactic value in the direction of the burst (3.6 x 10^21,\nKalberla et al. 2005). The counts to observed 0.3-10 keV flux\nconversion factor deduced from this spectrum is 5.0 x 10^-11 erg cm^-2\ns^-1 count^-1.\n\nIf the light curve continues to decay with a slope of 1.05, the count\nrate at 24 hours post-trigger will be 1.8 x 10^-3, corresponding to an\nobserved (unabsorbed) flux of 9.0 x 10^-14 (4.2 x 10^-13) erg cm^-2\ns^-1.\n\nThis circular is an official product of the Swift-XRT team.",
  "circularId": 8031,
  "createdOn": 1217179000000,
  "email": "pae9@star.le.ac.uk",
  "subject": "GRB 080727B: Swift-XRT refined analysis",
  "submitter": "Phil Evans at U of Leicester  <pae9@star.le.ac.uk>",
  "eventId": "GRB 080727B"
}