{
  "bibcode": "2014GCN.16562....1D",
  "body": "M. de Pasquale (INAF-IASFPA), M.C. Stroh (PSU), D.N. Burrows (PSU),\nJ.A. Kennea (PSU), B.P. Gompertz (U. Leicester), J.P. Osborne (U.\nLeicester), K.L. Page (U. Leicester), A. Maselli  (INAF-IASFPA), A.\nMelandri (INAF-OAB) and C.A. Swenson report on behalf of the Swift-XRT\nteam:\n\nWe have analysed 10.0 ks of XRT data for GRB 140709B (Swenson  et al.\nGCN Circ. 16551),  from 85 s to 28.9 ks after the  BAT trigger. The\ndata comprise 207 s in Windowed Timing (WT) mode (the first 4 s were\ntaken while Swift was slewing) with the remainder in Photon Counting\n(PC) mode. The enhanced XRT position for this burst was given by Goad\net al. (GCN Circ. 16556).\n\nThe late-time light curve (from T0+4.8 ks) can be modelled with  a\npower-law decay with a decay index of alpha=0.99 (+0.13, -0.12).\n\nA spectrum formed from the WT mode data can be fitted with an absorbed\npower-law with a photon spectral index\tof 1.14 (+/-0.07). The\nbest-fitting absorption column is  2.2 (+0.5, -0.4) x 10^21 cm^-2, in\nexcess of the Galactic value of 4.3 x 10^20 cm^-2 (Willingale et al.\n2013). The PC mode spectrum has a photon index of 2.05 (+0.14, -0.13)\nand a best-fitting absorption column of 1.9 (+/-0.4) x 10^21 cm^-2. The\ncounts to observed (unabsorbed) 0.3-10 keV flux conversion factor\ndeduced from this spectrum  is 3.4 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     1.9 (+/-0.4) x 10^21 cm^-2\nGalactic foreground: 4.3 x 10^20 cm^-2\nExcess significance: 5.7 sigma\nPhoton index:\t     2.05 (+0.14, -0.13)\n\nIf the light curve continues to decay with a power-law decay index of\n0.99, the count rate at T+24 hours will be 0.010 count s^-1,\ncorresponding to an observed (unabsorbed) 0.3-10 keV flux of 3.5 x\n10^-13 (4.9 x 10^-13) erg cm^-2 s^-1.\n\nThe results of the XRT-team automatic analysis are available at\nhttp://www.swift.ac.uk/xrt_products/00603866.\n\nThis circular is an official product of the Swift-XRT team.",
  "circularId": 16562,
  "createdOn": 1404966544000,
  "email": "pae9@leicester.ac.uk",
  "subject": "GRB 140709B: Swift-XRT refined Analysis",
  "submitter": "Phil Evans at U of Leicester  <pae9@leicester.ac.uk>",
  "eventId": "GRB 140709B"
}