{
  "bibcode": "2014GCN.16033....1S",
  "body": "B. Sbarufatti (INAF-OAB/PSU), P. D'Avanzo (INAF-OAB), V. D'Elia (ASDC),\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 E. Troja report on behalf of the Swift-XRT team:\n\nWe have analysed 6.3 ks of XRT data for GRB 140323A (Troja  et al. GCN\nCirc. 16027),  from 90 s to 34.5 ks after the  BAT trigger. The data\ncomprise 650 s in Windowed Timing (WT) mode (the first 6 s were taken\nwhile Swift was slewing) with the remainder in Photon Counting (PC)\nmode. The enhanced XRT position for this burst was given by Osborne et\nal. (GCN Circ. 16028).\n\nThe late-time light curve (from T0+5.7 ks) can be modelled with  a\npower-law decay with a decay index of alpha=1.30 (+/-0.09).\n\nA spectrum formed from the WT mode data can be fitted with an absorbed\npower-law with a photon spectral index\tof 1.73 (+/-0.06). The\nbest-fitting absorption column is  5.0 (+/-0.4) x 10^21 cm^-2, in\nexcess of the Galactic value of 7.9 x 10^20 cm^-2 (Willingale et al.\n2013). The PC mode spectrum has a photon index of 2.00 (+/-0.12) and a\nbest-fitting absorption column of 5.3 (+/-0.7) x 10^21 cm^-2. The\ncounts to observed (unabsorbed) 0.3-10 keV flux conversion factor\ndeduced from this spectrum  is 4.2 x 10^-11 (6.8 x 10^-11) erg cm^-2\ncount^-1. \n\nA summary of the PC-mode spectrum is thus:\nTotal column:\t     5.3 (+/-0.7) x 10^21 cm^-2\nGalactic foreground: 7.9 x 10^20 cm^-2\nExcess significance: 10.8 sigma\nPhoton index:\t     2.00 (+/-0.12)\n\nIf the light curve continues to decay with a power-law decay index of\n1.30, the count rate at T+24 hours will be 0.033 count s^-1,\ncorresponding to an observed (unabsorbed) 0.3-10 keV flux of 1.4 x\n10^-12 (2.3 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/00592916.\n\nThis circular is an official product of the Swift-XRT team.",
  "circularId": 16033,
  "createdOn": 1395625205000,
  "email": "pae9@leicester.ac.uk",
  "subject": "GRB 140323A: Swift-XRT refined Analysis",
  "submitter": "Phil Evans at U of Leicester  <pae9@leicester.ac.uk>",
  "eventId": "GRB 140323A"
}