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GCN Circular 31263

GRB 211216A: Fermi GBM observation
2021-12-18T09:27:56Z (2 years ago)
Elisabetta Bissaldi at INFN,Bari <>
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:

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