{
  "bibcode": "2017GCN.20454....1M",
  "body": "A. Melandri (INAF-OAB), P. D'Avanzo (INAF-OAB), A. Cholden-Brown (PSU),\nS. J. LaPorte (PSU), J.A. Kennea (PSU), J.P. Osborne (U. Leicester),\nK.L. Page (U. Leicester), B. Mingo (U. Leicester), V. D'Elia (ASDC) and\n report on behalf of the Swift-XRT team: report on behalf of the\nSwift-XRT team:\n\nWe have analysed 8.0 ks of XRT data for GRB 170113A, from 50 s to 19.1\nks after the  BAT trigger. The data comprise 243 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 late-time light curve (from T0+5.2 ks) can be modelled with a\npower-law decay with a decay index of alpha=1.14 (+/-0.10).\n\nA spectrum formed from the WT mode data can be fitted with an absorbed\npower-law with a photon spectral index\tof 1.88 (+/-0.07). The\nbest-fitting absorption column is  1.82 (+0.26, -0.24) x 10^21 cm^-2,\nin excess of the Galactic value of 1.1 x 10^21 cm^-2 (Willingale et al.\n2013). The PC mode spectrum has a photon index of 1.77 (+/-0.08) and a\nbest-fitting absorption column of 1.43 (+0.26, -0.25) x 10^21 cm^-2.\nThe counts to observed (unabsorbed) 0.3-10 keV flux conversion factor\ndeduced from this spectrum  is 3.9 x 10^-11 (4.7 x 10^-11) erg cm^-2\ncount^-1. \n\nA summary of the PC-mode spectrum is thus:\nTotal column:\t     1.43 (+0.26, -0.25) x 10^21 cm^-2\nGalactic foreground: 1.1 x 10^21 cm^-2\nExcess significance: 2.3 sigma\nPhoton index:\t     1.77 (+/-0.08)\n\nIf the light curve continues to decay with a power-law decay index of\n1.14, the count rate at T+24 hours will be 0.030 count s^-1,\ncorresponding to an observed (unabsorbed) 0.3-10 keV flux of 1.2 x\n10^-12 (1.4 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/00732526.\n\nThis circular is an official product of the Swift-XRT team.",
  "circularId": 20454,
  "createdOn": 1484334037000,
  "email": "pae9@leicester.ac.uk",
  "subject": "GRB 170113A: Swift-XRT refined Analysis",
  "submitter": "Phil Evans at U of Leicester  <pae9@leicester.ac.uk>",
  "eventId": "GRB 170113A"
}