{
  "bibcode": "2017GCN.20431....1E",
  "body": "P.A. Evans (U. Leicester), V. D'Elia (ASDC), A. D'Ai (INAF-IASFPA), A.\nMelandri (INAF-OAB), B. Sbarufatti (INAF-OAB/PSU), D.N. Burrows (PSU),\nT.G.R. Roegiers (PSU), S.L. Gibson (U. Leicester), J.P. Osborne (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 170111A, from 96 s to 42.0\nks after the  BAT trigger. The data comprise 17 s in Windowed Timing\n(WT) mode (the first 4 s were taken while Swift was slewing) with the\nremainder in Photon Counting (PC) mode. \n\nThe late-time light curve (from T0+5.1 ks) can be modelled with a\npower-law decay with a decay index of alpha=0.72 (+/-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 1.68 (+0.17, -0.16). The\nbest-fitting absorption column is  3.6 (+0.9, -0.8) x 10^21 cm^-2, in\nexcess of the Galactic value of 3.1 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 4.6 x 10^-11 (6.1 x 10^-11) erg\ncm^-2 count^-1. \n\nA summary of the PC-mode spectrum is thus:\nTotal column:\t     3.6 (+0.9, -0.8) x 10^21 cm^-2\nGalactic foreground: 3.1 x 10^20 cm^-2\nExcess significance: 6.6 sigma\nPhoton index:\t     1.68 (+0.17, -0.16)\n\nIf the light curve continues to decay with a power-law decay index of\n0.72, the count rate at T+24 hours will be 0.020 count s^-1,\ncorresponding to an observed (unabsorbed) 0.3-10 keV flux of 9.5 x\n10^-13 (1.2 x 10^-12) erg cm^-2 s^-1.\n\nThe results of the XRT-team automatic analysis are available at\nhttp://www.swift.ac.uk/xrt_products/00731887.\n\nThis circular is an official product of the Swift-XRT team.",
  "circularId": 20431,
  "createdOn": 1484157130000,
  "email": "pae9@leicester.ac.uk",
  "subject": "GRB 170111A: Swift-XRT refined Analysis",
  "submitter": "Phil Evans at U of Leicester  <pae9@leicester.ac.uk>",
  "eventId": "GRB 170111A"
}