GCN Circular 32224
Subject
GRB 220617A: Fermi GBM observation
Date
2022-06-19T01:54:39Z (3 years ago)
From
Joshua Wood at MSFC/Fermi-GBM <joshua.r.wood@nasa.gov>
J. Wood (NASA/MSFC) reports on behalf of the Fermi GBM Team:
"At 18:31:12.89 UT on 17 June 2022, the Fermi Gamma-Ray Burst Monitor (GBM)
triggered and located GRB 220617A (trigger 677183477 / 220617772).
which was also detected by the Fermi-LAT (N. Di Lalla et al. 2022, GCN 32212).
The Fermi GBM Final Real-time Localization (GCN 32209) is consistent with the LAT position.
The GBM light curve consists of a single pulse
with a duration (T90) of about 0.7 s (50-300 keV).
The time-averaged spectrum from T0-0.1 s to T0+0.5 s is
well fit by a power law function with an exponential
high-energy cutoff. The power law index is -0.7 +/- 0.1 and
the cutoff energy, parameterized as Epeak, is 2.3 +/- 0.3 MeV.
The event fluence (10-1000 keV) in this time interval is
(2.3 +/- 0.1)E-06 erg/cm^2. The 64-ms peak photon flux measured
starting from T0+0.2 s in the 10-1000 keV band is 10 +/- 1 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/"