James DeLaunay (UAlabama), Aaron Tohuvavohu (U Toronto), Gayathri
Raman (PSU), Jamie A. Kennea (PSU), report:
Swift/BAT did not localize GRB 220107A onboard (T0:
2022-01-07T14:45:31 UTC, Fermi/GBM GCN 31399), due to a slew.
The Fermi notice, distributed in near real-time, triggered the Swift
Mission Operations Center operated Gamma-ray Urgent Archiver for Novel
Opportunities (GUANO; Tohuvavohu et al. 2020, ApJ, 900, 1).
Upon trigger by this notice, GUANO sent a command to the Swift Burst
Alert Telescope (BAT) to save 200 seconds of BAT event-mode data from
[-50,+150] seconds around the time of the burst. All the requested
event mode data was delivered to the ground.
The burst is detected in BAT, on the approach to SAA and during a slew.
The location was found in a mosaiced slew image with an SNR ~9.
The BAT position is
RA, Dec = 169.761, 34.139 deg which is
RA(J2000) = 11h 19m 02.58s
Dec(J2000) = 34d 08��� 19.26���
with an estimated uncertainty of 10 arcmin.
The position is consistent with the Fermi/GBM RoboBA (GCN 31399) and
BALROG (GCN 31400) localizations.
XRT and UVOT follow-up has been requested.
Results of follow-up observations will be reported in future circulars.
GUANO is a fully autonomous, extremely low latency, spacecraft
commanding pipeline designed for targeted recovery of BAT event mode
data around the times of compelling astrophysical events to enable
more sensitive GRB searches.
A live reporting of Swift/BAT event data recovered by GUANO can be
found at: https://www.swift.psu.edu/guano/