{
  "bibcode": "2021GCN.31176....1D",
  "body": "James DeLaunay (UAlabama), Aaron Tohuvavohu (U Toronto), Gayathri\nRaman (PSU), Jamie A. Kennea (PSU), report:\n\nSwift/BAT detected a rate increase onboard (trigger ##1088092) but did\nnot localize GRB 211206A (T0: 2021-12-06T19:51:10 UTC, AGILE/MCAL GCN\n31175, CALET trig #1322855382).\n\nThe CALET 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 90 seconds of BAT event-mode data from\n[-45,+45] 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 74.6 in a\n4.096 s analysis time bin.\nEstimated T90 in the detector is 6.6 +/- 0.2 s (15-350 keV).\n\nNITRATES results strongly prefer an origin for the burst coming from\noutside the coded FOV, with DeltaLLHOut of -55.5.\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": 31176,
  "createdOn": 1638844926000,
  "email": "aaron.tohu@gmail.com",
  "subject": "GRB 211206A: Swift/BAT-GUANO detection outside the coded FOV",
  "submitter": "Aaron Tohuvavohu at U Toronto  <aaron.tohu@gmail.com>",
  "eventId": "GRB 211206A"
}