{
  "bibcode": "2019GCN.26144....1G",
  "body": "J. D. Gropp (PSU), J.P. Osborne (U. Leicester), K.L. Page (U.\nLeicester), A.P. Beardmore (U. Leicester), M. Capalbi (INAF-IASFPA), M.\nPerri (ASDC), V. D'Elia (ASDC), A. Tohuvavohu (U. Toronto), J.A. Kennea\n(PSU) and A. D'Ai report on behalf of the Swift-XRT team:\n\nWe have analysed 7.9 ks of XRT data for GRB 191101A (D'Ai et al. GCN\nCirc. 26135), from 92 s to 24.5 ks after the  BAT trigger. The data\ncomprise 190 s in Windowed Timing (WT) mode (the first 5 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 Beardmore\net al. (GCN Circ. 26137). The late-time light curve (from T0+4.8 ks) is\nconsistent with a constant source of mean count rate 4.8e+00 ct/sec. A\npower-law fit gives an index of 0.18 (+0.22, -0.21).\n\nA spectrum formed from the WT mode data can be fitted with an absorbed\npower-law with a photon spectral index\tof 2.28 (+/-0.05). The\nbest-fitting absorption column is  9.9 (+1.2, -1.1) x 10^20 cm^-2, in\nexcess of the Galactic value of 1.3 x 10^20 cm^-2 (Willingale et al.\n2013). The PC mode spectrum has a photon index of 2.08 (+0.15, -0.14)\nand a best-fitting absorption column of 6.2 (+3.2, -2.9) x 10^20 cm^-2.\nThe counts to observed (unabsorbed) 0.3-10 keV flux conversion factor\ndeduced from this spectrum  is 3.1 x 10^-11 (3.7 x 10^-11) erg cm^-2\ncount^-1. \n\nA summary of the PC-mode spectrum is thus:\nTotal column:\t     6.2 (+3.2, -2.9) x 10^20 cm^-2\nGalactic foreground: 1.3 x 10^20 cm^-2\nExcess significance: 2.8 sigma\nPhoton index:\t     2.08 (+0.15, -0.14)\n\nThe results of the XRT-team automatic analysis are available at\nhttp://www.swift.ac.uk/xrt_products/00932742.\n\nThis circular is an official product of the Swift-XRT team.",
  "circularId": 26144,
  "createdOn": 1572676490000,
  "email": "pae9@leicester.ac.uk",
  "subject": "GRB 191101A: Swift-XRT refined Analysis",
  "submitter": "Phil Evans at U of Leicester  <pae9@leicester.ac.uk>",
  "eventId": "GRB 191101A"
}