TITLE:   GCN CIRCULAR
NUMBER:  32834
SUBJECT: GRB 221022A: Fermi GBM detection
DATE:    22/10/24 21:35:01 GMT
FROM:    Suraj Poolakkil at UAH  <sp0076@uah.edu>

S. Poolakkil (UAH) and C. Meegan (UAH)
report on behalf of the Fermi GBM Team:

"At 19:33:33.55 UT on 22 October 2022, the Fermi Gamma-Ray Burst Monitor
(GBM)
triggered and located GRB 221022A (trigger 688160018 / 221022815, GCN 32816)
which was also detected by the Swift/BAT- GUANO (Tohuvavohu et al. 2022,
GCN 32824).
The Fermi GBM Final Real-time Localization is consistent
with the Swift-BAT GUANO position.

The angle from the Fermi LAT boresight at the GBM trigger time is 115
degrees.

The GBM light curve consists of a single peak followed
by some extended emission with a duration (T90) of about 7 s (50-300 keV).
The time-averaged spectrum from T0-3.07 s to T0 s
is best fit by a simple power law function with
index -1.39 +/- 0.15.

The event fluence (10-1000 keV) in this time interval is
(3.64 +/- 0.98)E-07  erg/cm^2. The 1-sec peak photon flux measured
starting from T0-1.6 s in the 10-1000 keV band
is 3.3 +/- 0.4 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/"