{
  "bibcode": "2022GCN.32491....1T",
  "body": "A. Tohuvavohu (U. Toronto), J.P. Osborne (U. Leicester), K.L. Page (U.\nLeicester), A.P. Beardmore (U. Leicester), P. D'Avanzo (INAF-OAB), M.G.\nBernardini (INAF-OAB), E. Ambrosi  (INAF-IASFPA) , D.N. Burrows (PSU),\nJ. D. Gropp (PSU) and R. Caputo report on behalf of the Swift-XRT team:\n\nWe have analysed 6.5 ks of XRT data for GRB 220826A (Caputo et al. GCN\nCirc. 32484), from 70 s to 33.8 ks after the  BAT trigger. The data\ncomprise 37 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 Beardmore\net al. (GCN Circ. 32485).\n\nThe late-time light curve (from T0+5.0 ks) can be modelled with a\npower-law decay with a decay index of alpha=1.25 (+/-0.18).\n\nA spectrum formed from the PC mode data can be fitted with an absorbed\npower-law with a photon spectral index of 1.80 (+0.16, -0.15). The\nbest-fitting absorption column is  1.6 (+/-0.5) x 10^21 cm^-2, in\nexcess of the Galactic value of 9.1 x 10^20 cm^-2 (Willingale et al.\n2013). The counts to observed (unabsorbed) 0.3-10 keV flux conversion\nfactor deduced from this spectrum  is 3.9 x 10^-11 (4.8 x 10^-11) erg\ncm^-2 count^-1. \n\nA summary of the PC-mode spectrum is thus:\nTotal column:\t     1.6 (+/-0.5) x 10^21 cm^-2\nGalactic foreground: 9.1 x 10^20 cm^-2\nExcess significance: 2.4 sigma\nPhoton index:\t     1.80 (+0.16, -0.15)\n\nIf the light curve continues to decay with a power-law decay index of\n1.25, the count rate at T+24 hours will be 5.0 x 10^-3 count s^-1,\ncorresponding to an observed (unabsorbed) 0.3-10 keV flux of 2.0 x\n10^-13 (2.4 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/01121751.\n\nThis circular is an official product of the Swift-XRT team.",
  "circularId": 32491,
  "createdOn": 1661561359000,
  "email": "pae9@leicester.ac.uk",
  "subject": "GRB 220826A: Swift-XRT refined Analysis",
  "submitter": "Phil Evans at U of Leicester  <pae9@leicester.ac.uk>",
  "eventId": "GRB 220826A"
}