{
  "bibcode": "2021GCN.31047....1D",
  "body": "James DeLaunay (UAlabama), Aaron Tohuvavohu (U Toronto), Gayathri\nRaman (PSU), Jamie A. Kennea (PSU), report:\n\nSwift/BAT did not trigger on GRB 211105A (T0: 2021-11-05T04:35:20.2\nUTC, GECAM-B GCN #31046).\n\nThe GECAM notice, distributed in near real-time, triggered the Swift\nMission Operations Center operated Gamma-ray Urgent Archiver for Novel\nOpportunities (GUANO; Tohuvavohu et al. 2020, ApJ, 900, 1).\n\nUpon trigger by this notice, GUANO sent a command to the Swift Burst\nAlert Telescope (BAT) to save 200 seconds of BAT event-mode data from\n[-50,+150] seconds around the time of the burst. All the requested\nevent mode data was delivered to the ground.\n\nThe BAT likelihood search, NITRATES (DeLaunay + Tohuvavohu,\narXiv:2111.01769), detects the burst with a sqrt(TS) of 16 in a 16.384\ns analysis time bin. This is the maximum test duration of the search\npipeline. The full burst duration in the detector is greater than 60\ns.\n\nNITRATES prefers an origin for this burst coming from outside the\ncoded FOV, with DeltaLLHOut of -4.\nAn out of FOV origin is consistent with the GECAM localization.\n\nSee Section 9.1 and Figure 20 in the NITRATES paper for brief\ndescriptions and interpretation of sqrt(TS), DeltaLLHPeak, and\nDeltaLLHOut.\n\nGUANO is a fully autonomous, extremely low latency, spacecraft\ncommanding pipeline designed for targeted recovery of BAT event mode\ndata around the times of compelling astrophysical events to enable\nmore sensitive GRB searches.\n\nA live reporting of Swift/BAT event data recovered by GUANO can be\nfound at: https://www.swift.psu.edu/guano/",
  "circularId": 31047,
  "createdOn": 1636164909000,
  "email": "aaron.tohu@gmail.com",
  "subject": "GRB 211105A: Swift/BAT-GUANO detection outside the coded FOV",
  "submitter": "Aaron Tohuvavohu at U Toronto  <aaron.tohu@gmail.com>",
  "eventId": "GRB 211105A"
}