GCN Circular 31263
Subject
GRB 211216A: Fermi GBM observation
Date
2021-12-18T09:27:56Z (3 years ago)
From
Elisabetta Bissaldi at INFN,Bari <elisabetta.bissaldi@ba.infn.it>
E. Bissaldi (Politecnico and INFN Bari) and C. Meegan (UAH)
report on behalf of the Fermi GBM Team:
"At 06:45:52.06 UT on 16 December 2021, the Fermi Gamma-Ray Burst Monitor (GBM)
triggered and located GRB 211216A (trigger 661329957 / 211216282),
which was also detected by the Swift/BAT-GUANO (Tohuvavohu et al. 2021, GCN 31250)
and by GECAM-B (Xue et al. 2021, GCN 31240).
The GBM on-ground location is reported in GCN 31237.
The GBM light curve shows a FRED-like emission episode
with a duration (T90) of about 20 s (50-300 keV).
The time-averaged spectrum from T0 to T0+20 s is
well fit by a power law function with an exponential
high-energy cutoff. The power law index is -0.47 +/- 0.05 and
the cutoff energy, parameterized as Epeak, is 208 +/- 7 keV.
The event fluence (10-1000 keV) in this time interval is
(9.16 +/- 0.02)E-06 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+6.3 s in the 10-1000 keV band
is 5.4 +/- 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/"