{
  "bibcode": "2017GCN.20558....1O",
  "body": "J.P. Osborne (U. Leicester), K.L. Page (U. Leicester), V. D'Elia\n(ASDC), A. D'Ai (INAF-IASFPA), A. Melandri (INAF-OAB), S. J. LaPorte\n(PSU), J.A. Kennea (PSU), B. Sbarufatti (INAF-OAB/PSU), B. Mingo (U.\nLeicester) and\treport on behalf of the Swift-XRT team: report on\nbehalf of the Swift-XRT team:\n\nWe have analysed 6.2 ks of XRT data for GRB 170127A, from 86 s to 58.8\nks after the  BAT trigger. The data comprise 168 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 an initial power-law decay with an\nindex of alpha=1.28 (+/-0.15), followed by a break at T+329 s to an\nalpha of 8.0 (+0.0, -1.1).\n\nA spectrum formed from the WT mode data can be fitted with an absorbed\npower-law with a photon spectral index\tof 1.49 (+/-0.10). The\nbest-fitting absorption column is  1.3 (+/-0.4) x 10^21 cm^-2, in\nexcess of the Galactic value of 8.5 x 10^20 cm^-2 (Willingale et al.\n2013). The counts to observed (unabsorbed) 0.3-10 keV flux conversion\nfactor deduced from this spectrum  is 4.5 x 10^-11 (5.0 x 10^-11) erg\ncm^-2 count^-1. \n\nA summary of the WT-mode spectrum is thus:\nTotal column:\t     1.3 (+/-0.4) x 10^21 cm^-2\nGalactic foreground: 8.5 x 10^20 cm^-2\nExcess significance: 2.0 sigma\nPhoton index:\t     1.49 (+/-0.10)\n\nIf the light curve continues to decay with a power-law decay index of\n5.19, the count rate at T+24 hours will be 2.0 x 10^-13 count s^-1,\ncorresponding to an observed (unabsorbed) 0.3-10 keV flux of 8.9 x\n10^-24 (10.0 x 10^-24) erg cm^-2 s^-1.\n\nThe results of the XRT-team automatic analysis are available at\nhttp://www.swift.ac.uk/xrt_products/00735326.\n\nThis circular is an official product of the Swift-XRT team.",
  "circularId": 20558,
  "createdOn": 1485601930000,
  "email": "pae9@leicester.ac.uk",
  "subject": "GRB 170127A: Swift-XRT refined Analysis",
  "submitter": "Phil Evans at U of Leicester  <pae9@leicester.ac.uk>",
  "eventId": "GRB 170127A"
}