TITLE:   GCN CIRCULAR
NUMBER:  31816
SUBJECT: GRB 220401A: Fermi GBM observation
DATE:    22/04/02 13:25:43 GMT
FROM:    Peter Veres at UAH  <veresp@gmail.com>

P. Veres (UAH), E. Bissaldi (Politecnico and INFN Bari) and C. Meegan (UAH)
report on behalf of the Fermi GBM Team:

"At 10:17:40.89 UT on 1 April 2022, the Fermi Gamma-Ray Burst Monitor (GBM)
triggered and located GRB 220401A (trigger 670501065 / 220401429).

The localization was reported in GCN 31811.

The GBM lightcurve consists of two emission episodes
with a duration (T90) of about 39.2 s (50-300 keV).
The time-averaged spectrum from T0-8.2 s to T0+38.9 s is
best fit by a power law function with an exponential
high-energy cutoff.  The power law index is -1.37 +/- 0.08
 and the cutoff energy, parameterized as Epeak, is 46 +/- 2 keV.

The event fluence (10-1000 keV) in this time interval is
(2.42 +/- 0.06)E-6 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+7.0 s in the 10-1000 keV band
is 7.8 +/- 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/"