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GCN Circular 27025

GRB 200120A: Fermi GBM observation
2020-02-09T02:01:37Z (4 years ago)
Rachel Hamburg at UAH <>
R. Hamburg (UAH) and C. Meegan (UAH)
report on behalf of the Fermi GBM Team:

"At 23:04:55.34 UT on 20 January 2020, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 200120A (trigger 601254300 / 200120962).
GRB 200120A was also detected by Insight/HMXT (GCN 26840) and AstroSat/CZTI
(GCN 26851), and localized by the IPN (GCN 26856).

Approximately 820 s after the GBM trigger, SRG/eRosita detected and
an X-ray transient consistent with being the afterglow of GRB 200120A
(Weber et al. 2019, GCN 26988). The Fermi GBM Final Real-time
Localization (GCN 26831) is consistent with the SRG/eRosita position.

The angle from the Fermi LAT boresight at the GBM trigger time is 148

The GBM light curve shows a broad, single-peaked structure
with a duration (T90) of about 13 s (50-300 keV).
The time-averaged spectrum from T0-6. to T0+10. s is
best fit by a power law function with an exponential
high-energy cutoff.  The power law index is -0.92 +/- 0.10 and
the cutoff energy, parameterized as Epeak, is 239 +/- 22 keV.

The event fluence (10-1000 keV) in this time interval is
(9.4 +/- 0.4)E-06 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+3.0 s in the 10-1000 keV band
is 13 +/- 1 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
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