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GCN Circular 16742

Subject
GRB 140821A: Fermi GBM Detection
Date
2014-08-25T16:44:54Z (11 years ago)
From
Binbin Zhang at UAH <binbin.zhang@uah.edu>
Bin-Bin Zhang (UAH) reports on behalf of the Fermi GBM Team:

"At 23:56:02.84 ��UT on the 21st of August 2014, the Fermi Gamma-Ray Burst��
Monitor triggered and located GRB 140821A (trigger 430358165 / 140821997).��
The trigger resulted in an Autonomous Repoint Request (ARR) that was��
accepted. The GBM on-ground location is consistent with the Fermi flight��
software position.

The angle from the Fermi LAT boresight is 93 degrees.

The GBM light curve consists of single peak with a duration (T90) of about
32 s (50-300 keV). The time-averaged spectrum from T0+11 s to T0+43 s is
well fit by Band function parameterized as Ep=483+/-22 keV,��
alpha=-0.82+/-0.03 and beta=-2.4+/-0.1.��

The event fluence (10-1000 keV) in this time interval is
(6.314+/-0.067)E-05 erg/cm^2. The 1.024-sec peak photon flux measured
starting from T0+29 s in the 10-1000 keV band is ��19.5+/-0.6 ph/s/cm^2.

The burst spectrum may be contaminated by solar flare activity that is��
detected at energies below ~20 keV in many of the same GBM detectors.��
Although the solar emission has several peaks, the first of which is ��
around T0+130 s, it may have significant overlap with the time of the
burst.

The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog.���
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