{
  "bibcode": "2022GCN.32930....1G",
  "body": "J. D. Gropp (PSU), S. Dichiara (PSU), J.A. Kennea (PSU), J.P. Osborne\n(U. Leicester), K.L. Page (U. Leicester), A.P. Beardmore (U.\nLeicester), B. Sbarufatti (INAF-OAB), A. D'Ai (INAF-IASFPA), A.\nMelandri (INAF-OAB) and M.A. Williams report on behalf of the Swift-XRT\nteam:\n\nWe have analysed 6.4 ks of XRT data for GRB 221110A (Williams et al.\nGCN Circ. 32925), from 64 s to 40.0 ks after the  BAT trigger. The data\ncomprise 55 s in Windowed Timing (WT) mode (the first 9 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 Evans et\nal. (GCN Circ. 32929).\n\nThe light curve can be modelled with a power-law decay with a decay\nindex of alpha=0.971 (+0.028, -0.027).\n\nA spectrum formed from the PC mode data can be fitted with an absorbed\npower-law with a photon spectral index of 1.88 (+/-0.15). The\nbest-fitting absorption column is  8 (+14, -8) x 10^21 cm^-2, at a\nredshift of 4.06, in addition to the Galactic value of 1.5 x 10^20\ncm^-2 (Willingale et al. 2013). The counts to observed (unabsorbed)\n0.3-10 keV flux conversion factor deduced from this spectrum  is 3.4 x\n10^-11 (3.6 x 10^-11) erg cm^-2 count^-1. \n\nA summary of the PC-mode spectrum is thus:\nGalactic foreground: 1.5 x 10^20 cm^-2\nIntrinsic column:    8 (+14, -8) x 10^21 cm^-2 at z=4.06\nPhoton index:\t     1.88 (+/-0.15)\n\nIf the light curve continues to decay with a power-law decay index of\n0.971, the count rate at T+24 hours will be 9.2 x 10^-3 count s^-1,\ncorresponding to an observed (unabsorbed) 0.3-10 keV flux of 3.1 x\n10^-13 (3.3 x 10^-13) erg cm^-2 s^-1.\n\nThe results of the XRT-team automatic analysis are available at\nhttp://www.swift.ac.uk/xrt_products/01136936.\n\nThis circular is an official product of the Swift-XRT team.",
  "circularId": 32930,
  "createdOn": 1668097462000,
  "email": "pae9@leicester.ac.uk",
  "subject": "GRB 221110A: Swift-XRT refined Analysis",
  "submitter": "Phil Evans at U of Leicester  <pae9@leicester.ac.uk>",
  "eventId": "GRB 221110A"
}