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GCN Circular 32089

GRB 220521A: Fermi GBM detection
2022-05-22T15:25:46Z (2 years ago)
Suraj Poolakkil at UAH <>
S. Poolakkil (UAH) and C. Meegan (UAH)
report on behalf of the Fermi GBM Team:

"At 23:20:21.73 UT on 21 May 2022, the Fermi Gamma-Ray Burst Monitor (GBM)
triggered and located GRB 220521A (trigger 674868026 / 220521972)
which was also detected by the Swift/BAT (Dichiara et al. 2022, GCN 32076).
The Fermi GBM Final Real-time Localization (GCN 32075) is consistent with
the Swift/BAT position.

The angle from the Fermi LAT boresight at the GBM trigger time is 105

The GBM light curve consists of multiple peaks followed
by some extended emission with a duration (T90) of about 14 s (50-300 keV).
The time-averaged spectrum from T0-1.024 s to T0+3.072 s
is best fit by a power law function with an exponential
high-energy cutoff. The power law index is -1.51 +/- 0.23  and
the cutoff energy, parameterized as Epeak, is 37 +/- 7 keV.

The event fluence (10-1000 keV) in this time interval is
(6.62 +/- 0.49)E-07 erg/cm^2. The 1-sec peak photon flux measured
starting from T0-0.32 s in the 10-1000 keV band
is 6.3 +/- 0.4 ph/s/cm^2.

The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog:

For Fermi GBM data and info, please visit the official Fermi GBM Support
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