{
  "subject": "GRB 130625A: Swift-XRT refined Analysis",
  "eventId": "GRB 130625A",
  "bibcode": "2013GCN.14930....1K",
  "createdOn": 1372230904000,
  "circularId": 14930,
  "submitter": "Phil Evans at U of Leicester  <pae9@leicester.ac.uk>",
  "email": "pae9@leicester.ac.uk",
  "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), V.\nD'Elia (ASDC), A. Maselli  (INAF-IASFPA), V. Mangano (INAF-IASFPA) and\nD. Grupe report on behalf of the Swift-XRT team:\n\nWe have analysed 2.8 ks of XRT data for GRB 130625A (Grupe  et al. GCN\nCirc. 14923),  from 100 s to 25.1 ks after the\tBAT trigger. The data\ncomprise 34 s in Windowed Timing (WT) mode with the remainder in Photon\nCounting (PC) mode. The enhanced XRT position for this burst was given\nby Goad et al. (GCN. Circ 14924).\n\nThe light curve can be modelled with  a power-law decay with a decay\nindex of alpha=1.70 (+0.21, -0.23).\n\nA spectrum formed from the PC mode data can be fitted with an absorbed\npower-law with a photon spectral index of 2.2 (+0.7, -0.6). The\nbest-fitting absorption column is  4.8 (+3.3, -2.3) x 10^21 cm^-2, in\nexcess of the Galactic value of 1.1 x 10^21 cm^-2 (Kalberla et al.\n2005). The counts to observed (unabsorbed) 0.3-10 keV flux conversion\nfactor deduced from this spectrum  is 4.1 x 10^-11 (8.3 x 10^-11) erg\ncm^-2 count^-1. \n\nA summary of the PC-mode spectrum is thus:\nTotal column:\t     4.8 (+3.3, -2.3) x 10^21 cm^-2\nGalactic foreground: 1.1 x 10^21 cm^-2\nExcess significance: 2.6 sigma\nPhoton index:\t     2.2 (+0.7, -0.6)\n\nIf the light curve continues to decay with a power-law decay index of\n1.70, the count rate at T+24 hours will be 5.3 x 10^-5 count s^-1,\ncorresponding to an observed (unabsorbed) 0.3-10 keV flux of 2.2 x\n10^-15 (4.4 x 10^-15) erg cm^-2 s^-1.\n\nThe results of the XRT-team automatic analysis are available at\nhttp://www.swift.ac.uk/xrt_products/00558982.\n\nThis circular is an official product of the Swift-XRT team."
}