{
  "bibcode": "2014GCN.16941....1D",
  "body": "P. D'Avanzo (INAF-OAB), V. D'Elia (ASDC), M. de Pasquale (INAF-IASFPA),\nM.C. Stroh (PSU), D.N. Burrows (PSU), J.A. Kennea (PSU), A.P. Beardmore\n(U. Leicester), P.A. Evans (U. Leicester), B.P. Gompertz (U. Leicester)\nand A. Vargas report on behalf of the Swift-XRT team:\n\nWe have analysed 10 ks of XRT data for GRB 141022A (Vargas  et al. GCN\nCirc. 16938),  from 144 s to 25.5 ks after the\tBAT trigger. The data\nare entirely in Photon Counting (PC) mode. The best available XRT\nposition  (using the promptly downlinked event data, the XRT-UVOT\nalignment and matching UVOT field sources to the USNO-B1 catalogue) is\nRA, Dec = 241.8696, -72.1254 which is equivalent to:\n\nRA (J2000): 16 07 28.70\nDec(J2000): -72 07 31.4\n\nwith an uncertainty of 2.1 arcsec (radius, 90% confidence).\n\nThe light curve can be modelled with  a power-law decay with a decay\nindex of alpha=1.21 (+/-0.08).\n\nA spectrum formed from the PC mode data can be fitted with an absorbed\npower-law with a photon spectral index of 2.5 (+0.5, -0.4). The\nbest-fitting absorption column is  1.1 (+0.5, -0.4) x 10^22 cm^-2, in\nexcess of the Galactic value of 1.0 x 10^21 cm^-2 (Willingale et al.\n2013). The counts to observed (unabsorbed) 0.3-10 keV flux conversion\nfactor deduced from this spectrum  is 3.9 x 10^-11 (1.2 x 10^-10) erg\ncm^-2 count^-1. \n\nA summary of the PC-mode spectrum is thus:\nTotal column:\t     1.1 (+0.5, -0.4) x 10^22 cm^-2\nGalactic foreground: 1.0 x 10^21 cm^-2\nExcess significance: 4.5 sigma\nPhoton index:\t     2.5 (+0.5, -0.4)\n\nIf the light curve continues to decay with a power-law decay index of\n1.21, the count rate at T+24 hours will be 2.7 x 10^-4 count s^-1,\ncorresponding to an observed (unabsorbed) 0.3-10 keV flux of 1.0 x\n10^-14 (3.3 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/00616061.\n\nThis circular is an official product of the Swift-XRT team.",
  "circularId": 16941,
  "createdOn": 1413985684000,
  "email": "pae9@leicester.ac.uk",
  "subject": "GRB 141022A: Swift-XRT refined Analysis",
  "submitter": "Phil Evans at U of Leicester  <pae9@leicester.ac.uk>",
  "eventId": "GRB 141022A"
}