GCN Circular 29578
Subject
GRB 210226A: Fermi GBM detection
Date
2021-02-27T03:20:46Z (3 years ago)
From
Joshua Wood at MSFC/Fermi-GBM <joshua.r.wood@nasa.gov>
J. Wood (NASA/MSFC) and C. Meegan (UAH)
report on behalf of the Fermi GBM Team:
"At 04:43:56.56 UT on 26 February 2021, the Fermi Gamma-Ray Burst Monitor (GBM)
triggered and located GRB 210226A (trigger 636007441 / 210226197)
which was also detected by the Swift/BAT and Swift/XRT (A.P. Beardmore et al. 2019, GCN 29568).
The GBM on-ground location is consistent with the Swift position.
The angle from the Fermi LAT boresight at the GBM trigger time is 58.6 degrees.
The GBM light curve consists of a single peak
with a duration (T90) of about 26 s (50-300 keV).
The time-averaged spectrum from T0-6 s to T0+18 s is
best fit by a power law function with an exponential
high-energy cutoff. The power law index is -1.2 +/- 0.1 and
the cutoff energy, parameterized as Epeak, is 170 +/- 29 keV
The event fluence (10-1000 keV) in this time interval is
(2.7 +/- 0.2)E-06 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+1.2 s in the 10-1000 keV band
is 4.1 +/- 0.2 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/"