{
  "bibcode": "2022GCN.32651....1K",
  "body": "J.A. Kennea (PSU), A. Tohuvavohu (U. Toronto), J.P. Osborne (U.\nLeicester), K.L. Page (U. Leicester), A.P. Beardmore (U. Leicester), A.\nMelandri (INAF-OAB), T. Sbarrato (INAF-OAB), P. D'Avanzo (INAF-OAB),\nD.N. Burrows (PSU) and E Bissaldi report on behalf of the Swift-XRT\nteam:\n\nWe have analysed 12 ks of XRT data for GRB 221009A (E Bissaldi et al.\nGCN Circ. 32637), from 159 s to 58.4 ks after the  BAT trigger. The\ndata are entirely in Windowed Timing (WT) mode (the first 10 s were\ntaken while Swift was slewing). A spectrum formed from the WT mode data\ncan be fitted with an absorbed power-law with a photon spectral index \nof 1.836 (+0.012, -0.011). The best-fitting absorption column is  6.76\n(+/-0.16) x 10^21 cm^-2, at a redshift of 0.151, in addition to the\nGalactic value of 5.4 x 10^21 cm^-2 (Willingale et al. 2013). The\ncounts to observed (unabsorbed) 0.3-10 keV flux conversion factor\ndeduced from this spectrum  is 5.7 x 10^-11 (1.0 x 10^-10) erg cm^-2\ncount^-1. \n\nA summary of the WT-mode spectrum is thus:\nGalactic foreground: 5.4 x 10^21 cm^-2\nIntrinsic column:    6.76 (+/-0.16) x 10^21 cm^-2 at z=0.151\nPhoton index:\t     1.836 (+0.012, -0.011)\n\nThe results of the XRT-team automatic analysis are available at\nhttp://www.swift.ac.uk/xrt_products/01126853.\n\nThis circular is an official product of the Swift-XRT team.",
  "circularId": 32651,
  "createdOn": 1665400776000,
  "email": "pae9@leicester.ac.uk",
  "subject": "GRB 221009A: Swift-XRT refined Analysis",
  "submitter": "Phil Evans at U of Leicester  <pae9@leicester.ac.uk>",
  "eventId": "GRB 221009A"
}