{
  "bibcode": "2017GCN.20535....1B",
  "body": "D.N. Burrows (PSU), P.A. Evans (U. Leicester), S.L. Gibson (U.\nLeicester), J.P. Osborne (U. Leicester), A. Melandri (INAF-OAB), P.\nD'Avanzo (INAF-OAB), V. D'Elia (ASDC), A. Cholden-Brown (PSU), S. J.\nLaPorte (PSU) and  report on behalf of the Swift-XRT team: report on\nbehalf of the Swift-XRT team:\n\nWe have analysed 7.0 ks of XRT data for GRB 170126A, from 73 s to 40.7\nks after the  BAT trigger. The data comprise 68 s in Windowed Timing\n(WT) mode (the first 7 s were taken while Swift was slewing) with the\nremainder in Photon Counting (PC) mode. \n\nThe light curve can be modelled with a power-law decay with a decay\nindex of alpha=1.30 (+0.06, -0.05).\n\nA spectrum formed from the WT mode data can be fitted with an absorbed\npower-law with a photon spectral index\tof 1.52 (+0.33, -0.28). The\nbest-fitting absorption column is  2.0 (+2.5, -1.3) x 10^21 cm^-2,\nconsistent with the Galactic value of 7.0 x 10^20 cm^-2 (Willingale et\nal. 2013). The counts to observed (unabsorbed) 0.3-10 keV flux\nconversion factor deduced from this spectrum  is 4.5 x 10^-11 (5.3 x\n10^-11) erg cm^-2 count^-1. \n\nA summary of the WT-mode spectrum is thus:\nTotal column:\t     2.0 (+2.5, -1.3) x 10^21 cm^-2\nGalactic foreground: 7.0 x 10^20 cm^-2\nExcess significance: <1.6 sigma\nPhoton index:\t     1.52 (+0.33, -0.28)\n\nIf the light curve continues to decay with a power-law decay index of\n1.30, the count rate at T+24 hours will be 9.2 x 10^-4 count s^-1,\ncorresponding to an observed (unabsorbed) 0.3-10 keV flux of 4.2 x\n10^-14 (4.9 x 10^-14) erg cm^-2 s^-1.\n\nThe results of the XRT-team automatic analysis are available at\nhttp://www.swift.ac.uk/xrt_products/00735188.\n\nThis circular is an official product of the Swift-XRT team.",
  "circularId": 20535,
  "createdOn": 1485492562000,
  "email": "pae9@leicester.ac.uk",
  "subject": "GRB 170126A: Swift-XRT refined Analysis",
  "submitter": "Phil Evans at U of Leicester  <pae9@leicester.ac.uk>",
  "eventId": "GRB 170126A"
}