{
  "bibcode": "2009GCN.10106....1G",
  "body": "D. Grupe (PSU) reports on behalf of the Swift-XRT team:\n\nWe have analyzed the first 7 orbits of  XRT data of GRB 091029\n(Grupe et al. GCN Circ.  10097). The data comprise 69 s in Windowed\nTiming (WT) mode and 15727 s in Photon Counting (PC) mode. The\nenhanced XRT position has already been determined by Goad et al.\n(GCN circ. 10102).\n\nA spectrum formed from the WT mode data can be fitted with an\nabsorbed  power-law with a photon spectral index of 2.30+/-0.08\nwith an  absorption column density consistent with the Galactic\nvalue of 1.14 x 10^20 cm^-2 (Kalberla et al. 2005). The PC mode\nspectrum (excluding the flare around 300 s after the burst) results\nin a slightly flatter X-ray spectrum with Gamma = 2.00+/-0.07.\n\nThe light curve (excluding the flares) can be modelled with a\ndouble broken power-law decay with an initial decay slope\nalpha-1 = 3.76+0.21-0.19 with the first break at 358+48-31 s\nafter the trigger followed by a plateau phase with a decay slope\nalpha-2 = -0.17+/-0.22 and a second break at 3640+3450-1270 s.\nAfter this break the decay slope is alpha-3 = 0.76+0.06-0.05.\nIf the afterglow continues to decay with a slope of 0.76, the\npredicted count rates 24, 48, and 72  hours after the trigger are\n0.033 counts s^-1 or 1.12e-12 ergs s^-1 cm^-2,\n0.020 counts s^-1 or 6.80e-13 ergs s^-1 cm^-2,\n0.014 counts s^-1 or 4.76e-13 ergs s^-1 cm^-2, respectively.\n\n\n\nThis circular is an official product of the Swift-XRT team.",
  "circularId": 10106,
  "createdOn": 1256845574000,
  "email": "grupe@astro.psu.edu",
  "subject": "GRB 091029: Swift XRT refined analysis",
  "submitter": "Dirk Grupe at PSU/Swift-XRT  <grupe@astro.psu.edu>",
  "eventId": "GRB 091029"
}