{
  "bibcode": "2016GCN.20185....1P",
  "body": "K.L. Page (U. Leicester), P. D'Avanzo (INAF-OAB), V. D'Elia (ASDC), A.\nD'Ai (INAF-IASFPA), D.N. Burrows (PSU), T.G.R. Roegiers (PSU), L.M.\nMcCauley (PSU), B. Mingo (U. Leicester), A.P. Beardmore (U. Leicester)\nand J.R. Cummings report on behalf of the Swift-XRT team:\n\nWe have analysed 7.7 ks of XRT data for GRB 161117A (Cummings et al.\nGCN Circ. 20179), from 52 s to 19.0 ks after the  BAT trigger. The data\ncomprise 384 s in Windowed Timing (WT) mode (the first 7 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 Goad et al.\n(GCN Circ. 20184).\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=0.92 (+/-0.09).\n\nA spectrum formed from the WT mode data can be fitted with an absorbed\npower-law with a photon spectral index\tof 1.322 (+/-0.028). The\nbest-fitting absorption column is  2.9 (+/-0.8) x 10^21 cm^-2, at a\nredshift of 1.549, in addition to the Galactic value of 4.4 x 10^20\ncm^-2 (Willingale et al. 2013). The PC mode spectrum has a photon index\nof 1.94 (+/-0.08) and a best-fitting absorption column of 7.4 (+1.9,\n-1.8) x 10^21 cm^-2. The counts to observed (unabsorbed) 0.3-10 keV\nflux conversion factor deduced from this spectrum  is 3.5 x 10^-11 (4.4\nx 10^-11) erg cm^-2 count^-1. \n\nA summary of the PC-mode spectrum is thus:\nGalactic foreground: 4.4 x 10^20 cm^-2\nIntrinsic column:    7.4 (+1.9, -1.8) x 10^21 cm^-2 at z=1.549\nPhoton index:\t     1.94 (+/-0.08)\n\nIf the light curve continues to decay with a power-law decay index of\n0.92, the count rate at T+24 hours will be 0.050 count s^-1,\ncorresponding to an observed (unabsorbed) 0.3-10 keV flux of 1.7 x\n10^-12 (2.2 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/00722604.\n\nThis circular is an official product of the Swift-XRT team.",
  "circularId": 20185,
  "createdOn": 1479384620000,
  "email": "pae9@leicester.ac.uk",
  "subject": "GRB 161117A: Swift-XRT refined Analysis",
  "submitter": "Phil Evans at U of Leicester  <pae9@leicester.ac.uk>",
  "eventId": "GRB 161117A"
}