{
  "bibcode": "2019GCN.23736....1B",
  "body": "A. P. Beardmore (U. Leicester) reports on behalf of the Swift-XRT Team:\n\nThe Swift-XRT Windowed Timing (WT) mode spectrum of GRB 190114C shows\nan apparent strong excess of emission below ~0.8 keV when compared to\na simple absorbed powerlaw model. The excess is not thought to be\nintrinsic to the GRB (e.g. an additional spectral component), but is\ninstead caused by a well-known instrumental effect whereby charge from\ndeep charge traps (formed by radiation damage to the CCD) is released\non a timescale comparable to the WT readout time (1.78ms). The\nreleased charge is subsequently detected in trailing readout rows\nas additional low energy events, causing excess emission to be seen at\nlow energies (see http://www.swift.ac.uk/analysis/xrt/digest_cal.php#trail).\nThe excess is more apparent in strongly absorbed sources such as this.\n\nThe XRT Team is developing software to identify and remove occurences\nof such trailing charge from WT data. In the meantime, the WT spectra\ncan be reliably modelled above ~0.8 keV.",
  "circularId": 23736,
  "createdOn": 1547639865000,
  "email": "ab271@leicester.ac.uk",
  "subject": "The Swift-XRT WT mode spectrum of GRB190114C",
  "submitter": "Andy Beardmore at U Leicester  <ab271@leicester.ac.uk>",
  "eventId": "GRB 190114C"
}