{
  "bibcode": "2012GCN.14029....1K",
  "body": "J.A. Kennea (PSU), M.C. Stroh (PSU), D.N. Burrows (PSU), J.P. Osborne\n(U. Leicester), K.L. Page (U. Leicester), C. Pagani (U. Leicester), P.\nD'Avanzo (INAF-OAB), V. D'Elia (ASDC), A. Maselli  (INAF-IASFPA) and \nreport on behalf of the Swift-XRT team: report on behalf of the\nSwift-XRT team:\n\nWe have analysed 8.7 ks of XRT data for GRB 121201A (Yershov et al. et\nal. GCN Circ. 14025), from 101 s to 33.6 ks after the  BAT trigger. The\ndata comprise 24 s in Windowed Timing (WT) mode (the first 7 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\nBeardmore et al. (GCN. Circ 14027).\n\nThe light curve can be modelled with  a power-law decay with a decay\nindex of alpha=1.24 (+0.06, -0.05).\n\nA spectrum formed from the PC mode data can be fitted with an absorbed\npower-law with a photon spectral index of 1.62 (+0.15, -0.09). The\nbest-fitting absorption column is  2.15 (+3.39, -0.16) x 10^20 cm^-2,\nconsistent with the Galactic value of 2.0 x 10^20 cm^-2 (Kalberla et\nal. 2005). The counts to observed (unabsorbed) 0.3-10 keV flux\nconversion factor deduced from this spectrum  is 4.3 x 10^-11 (4.4 x\n10^-11) erg cm^-2 count^-1. \n\nA summary of the PC-mode spectrum is thus:\nTotal column:\t     2.15 (+3.39, -0.16) x 10^20 cm^-2\nGalactic foreground: 2.0 x 10^20 cm^-2\nExcess significance: <1.6 sigma\nPhoton index:\t     1.62 (+0.15, -0.09)\n\nIf the light curve continues to decay with a power-law decay index of\n1.24, the count rate at T+24 hours will be 1.4 x 10^-3 count s^-1,\ncorresponding to an observed (unabsorbed) 0.3-10 keV flux of 5.8 x\n10^-14 (6.0 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/00540178.\n\nThis circular is an official product of the Swift-XRT team.\n\n[GCN OPS NOTE(19dec12): Per author's request, in the first sentence\nthe Yershov/14025 reference was filled in.]",
  "circularId": 14029,
  "createdOn": 1354409285000,
  "email": "pae9@leicester.ac.uk",
  "subject": "GRB 121201A: Swift-XRT refined Analysis",
  "submitter": "Phil Evans at U of Leicester  <pae9@leicester.ac.uk>",
  "eventId": "GRB 121201A"
}