{
  "bibcode": "2010GCN.10847....1M",
  "body": "R. Margutti, B. Sbarufatti (INAF-OAB) and V. D'Elia (ASDC) report on\nbehalf of the Swift-XRT team:\n\nWe have analysed 1.1 ks of XRT data for GRB 100615A (D'Elia et al. GCN\nCirc. 10841), from 68 s to 1.2 ks after the BAT trigger. The data comprise\n73 s in Windowed Timing (WT) mode with the remainder in Photon Counting\n(PC) mode. The light curve can be modelled with an initial power-law decay\nwith an index of alpha=4.17 (+0.23, -0.22), followed by a break at T+191 s\nto an alpha of -0.03 (+0.23, -0.25).\n\nA spectrum formed from the WT mode data can be fitted with an absorbed\npower-law with a photon spectral index of 2.21 (+0.16, -0.15). The\nbest-fitting absorption column is 8.8 (+1.1, -1.0) x 10^21 cm^-2, in\nexcess of the Galactic value of 3.3 x 10^20 cm^-2 (Kalberla et al. 2005).\nThe PC mode spectrum has a photon index of 2.6 (+0.4, -0.3) and a\nbest-fitting absorption column of 1.18 (+0.29, -0.25) x 10^22 cm^-2. The\ncounts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced\nfrom this spectrum is 4.9 x 10^-11 (1.9 x 10^-10) erg cm^-2 count^-1.\n\nIf the light curve continues to decay with a power-law decay index of\n-0.03, the count rate at T+24 hours will be 1.4 count s^-1, corresponding\nto an observed (unabsorbed) 0.3-10 keV flux of 6.8 x 10^-11 (2.6 x 10^-10)\nerg cm^-2 s^-1.\n\nThe results of the XRT-team automatic analysis are available at\nhttp://www.swift.ac.uk/xrt_products/00424733.\n\nThis circular is an official product of the Swift-XRT team.",
  "circularId": 10847,
  "createdOn": 1276596164000,
  "email": "raffaella.margutti@brera.inaf.it",
  "subject": "GRB 100615A: Swift-XRT refined analysis",
  "submitter": "Raffaella Margutti at U. di Milano Bicocca  <raffaella.margutti@brera.inaf.it>",
  "eventId": "GRB 100615A"
}