TITLE:   GCN CIRCULAR
NUMBER:  32964
SUBJECT: GRB 221120A: Fermi GBM observation
DATE:    22/11/21 15:15:14 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 21:29:27.85 UT on 20 November 2022, the Fermi Gamma-Ray Burst Monitor (GBM)
triggered and located GRB 221120A (trigger 690672572 / 221120895)
which was also detected by the Swift/BAT (Eyles-Ferris et al., GCN 32955).
The GBM on-ground location is consistent with the Swift position.


The angle from the Fermi LAT boresight at the GBM trigger time is 62 degrees.


The GBM light curve consists of two pulses
with a duration (T90) of about 0.64 s (50-300 keV).
The time-averaged spectrum from T0-0.13 s to T0+0.58 s is
best fit by a power law function with an exponential
high-energy cutoff.  The power law index is 0.11 +/- 0.31 and
the cutoff energy, parameterized as Epeak, is 379 +/- 65 keV.

The event fluence (10-1000 keV) in this time interval is
(7.8 +/- 0.9)E-7 erg/cm^2. The 64 ms peak photon flux measured
starting from T0+0.38 s in the 10-1000 keV band
is 7.45 +/- 0.91 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/"