{
  "bibcode": "2019GCN.23683....1D",
  "body": "P. D'Avanzo (INAF-OAB), V. D'Elia (ASDC), A. D'Ai (INAF-IASFPA), J.A.\nKennea (PSU), B. Sbarufatti (INAF-OAB/PSU), D.N. Burrows (PSU), J.P.\nOsborne (U. Leicester), K.L. Page (U. Leicester), A.P. Beardmore (U.\nLeicester) and S.J. LaPorte report on behalf of the Swift-XRT team:\n\nWe have analysed 6.8 ks of XRT data for GRB 190114A (LaPorte et al. GCN\nCirc. 23677), from 235 s to 19.0 ks after the  BAT trigger. The data\ncomprise 64 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. 23679).\n\nThe light curve can be modelled with a series of power-law decays. The\ninitial decay index is alpha=7.87 (+0.13, -0.43). At T+403 s  the decay\nflattens to an alpha of 0.01 (+0.20, -0.17) before breaking again at\nT+2398 s to a final decay with index alpha=1.16 (+/-0.14).\n\nA spectrum formed from the WT mode data can be fitted with an absorbed\npower-law with a photon spectral index\tof 2.38 (+0.17, -0.12). The\nbest-fitting absorption column is  1 (+13, -1) x 10^21 cm^-2, at a\nredshift of 3.3765, in addition to the Galactic value of 1.6 x 10^21\ncm^-2 (Willingale et al. 2013). The PC mode spectrum has a photon index\nof 1.80 (+0.09, -0.08) and a best-fitting absorption column of 2 (+10,\n-2) x 10^21 cm^-2. The counts to observed (unabsorbed) 0.3-10 keV flux\nconversion factor deduced from this spectrum  is 3.9 x 10^-11 (4.8 x\n10^-11) erg cm^-2 count^-1. \n\nA summary of the PC-mode spectrum is thus:\nGalactic foreground: 1.6 x 10^21 cm^-2\nIntrinsic column:    2 (+10, -2) x 10^21 cm^-2 at z=3.3765\nPhoton index:\t     1.80 (+0.09, -0.08)\n\nIf the light curve continues to decay with a power-law decay index of\n1.16, the count rate at T+24 hours will be 0.013 count s^-1,\ncorresponding to an observed (unabsorbed) 0.3-10 keV flux of 5.0 x\n10^-13 (6.2 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/00883600.\n\nThis circular is an official product of the Swift-XRT team.",
  "circularId": 23683,
  "createdOn": 1547464894000,
  "email": "pae9@leicester.ac.uk",
  "subject": "GRB 190114A: Swift-XRT refined Analysis",
  "submitter": "Phil Evans at U of Leicester  <pae9@leicester.ac.uk>",
  "eventId": "GRB 190114A"
}