GCN Circular 26671

GRB 200107B: Fermi GBM observation

S. Lesage (UAH) and C. Meegan (UAH)
report on behalf of the Fermi GBM Team:

"At 19:26:22.81 UT on 07 January 2020, the Fermi Gamma-Ray Burst Monitor
(GBM)
triggered and located GRB 200107B (trigger 600117987 / 200107810),
which was also detected by the Swift/BAT (Bernardini et al. 2020, GCN
26661
Not found
 
 
).
The GBM on-ground location is consistent with the Swift position.

The angle from the Fermi LAT boresight at the GBM trigger time is 47
degrees.

The GBM light curve shows a complex, multi-peaked structure
with a duration (T90) of about 81 s (50-300 keV).
The time-averaged spectrum from T0+4 s to T0+44 s is
best fit by a power law function with an exponential
high-energy cutoff. The power law index is -1.1 +/- 0.1 and
the cutoff energy, parameterized as Epeak, is 412 +/- 138 keV.

The event fluence (10-1000 keV) in this time interval is
(1.29 +/- 0.15)E-05 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+41.0 s in the 10-1000 keV band is 3.3 +/- 0.3 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/"