{
  "bibcode": "2021GCN.31338....1R",
  "body": "Gayathri Raman (PSU), James DeLaunay (UAlabama), Aaron Tohuvavohu (U\nToronto),  Jamie A. Kennea (PSU), report:\n\nSwift/BAT did not localize GRB 211229C (T0: 2021-12-29T09:36:08\nUTC,INTEGRAL/SPI-ACS 9580).\n\nThe INTEGRAL notice, distributed in near real-time, triggered the\nSwift Mission Operations Center operated Gamma-ray Urgent Archiver for\nNovel Opportunities (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 10.4 in a\n4.096 s analysis time bin.\n\nNITRATES results, independently, are ambiguous with respect to whether\nthis burst originates from in or outside the BAT FOV, with a\nborderline DeltaLLHOut of 7 and no specific location in the FOV\npreferred.\n\nIndependent spectral or fluence measurements of this burst from other\ninstruments could help determine the preferred origin.\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": 31338,
  "createdOn": 1640827392000,
  "email": "aaron.tohu@gmail.com",
  "subject": "GRB 211229C: Swift/BAT-GUANO detection likely outside the coded FOV",
  "submitter": "Aaron Tohuvavohu at U Toronto  <aaron.tohu@gmail.com>",
  "eventId": "GRB 211229C"
}