TITLE:   GCN CIRCULAR
NUMBER:  31406
SUBJECT: GRB 220107A: Fermi GBM observations
DATE:    22/01/08 03:49:49 GMT
FROM:    Peter Veres at UAH  <veresp@gmail.com>

P. Veres  and C. Meegan (both UAH)
report on behalf of the Fermi GBM Team:

"At 14:45:31.93 UT on 7 January 2022, the Fermi Gamma-Ray Burst Monitor (GBM)
triggered and located GRB 220107A (trigger 663259536 / 220107615),
which was also detected by the Swift/BAT-GUANO (DeLaunay et al., GCN 31402).

The Fermi GBM Final Real-time Localization (GCN 31399) is consistent
with the Swift position.

The angle from the Fermi LAT boresight at the GBM trigger time is 78 degrees.

The GBM light curve shows multiple peaks
with a duration (T90) of about 33 s (50-300 keV).
The time-averaged spectrum from T0-0.3 s to T0+36.6 s is
best fit by a Band function with Epeak = 168 +/- 11 keV,
alpha = -0.55 +/- 0.06, and beta = -1.94 +/- 0.06.

The event fluence (10-1000 keV) in this time interval is
(2.24 +/- 0.05)E-5 erg/cm^2. The 1-sec peak photon flux measured
starting from T0 + 10.2 s in the 10-1000 keV band
is 13.9 +/- 0.3 ph/s/cm^2.


The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog:
https://heasarc.gsfc.nasa.gov/W3Browse/fermi/fermigbrst.html

For Fermi GBM data and info, please visit the official Fermi GBM Support Page:
https://fermi.gsfc.nasa.gov/ssc/data/access/gbm/"