TITLE:   GCN CIRCULAR
NUMBER:  31414
SUBJECT: GRB 220107B: Fermi GBM observations
DATE:    22/01/08 15:59:52 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 19:01:33.52 UT on 7 January 2022, the Fermi Gamma-Ray Burst Monitor (GBM)
triggered and located GRB 220107B (trigger 663274898 / 220107793),
which was also detected by the Fermi LAT (Arimoto et al., GCN 31409).
The GBM on-ground location is consistent with the LAT position.

The GBM light curve consists of multiple separated pulses
with a duration (T90) of about 25 s (50-300 keV).
The time-averaged spectrum from T0-1.7 s to T0+27 s is
best fit by a Band function with Epeak = 391 +/- 21 keV,
alpha = -0.86 +/- 0.03, and beta = -2.40 +/- 0.16.

The event fluence (10-1000 keV) in this time interval is
(2.68 +/- 0.03)E-5 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+12.0 s in the 10-1000 keV band
is 14.4 +/- 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/"