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GCN Circular 23044

GRB 180727A: Fermi GBM observation
2018-07-27T19:30:47Z (6 years ago)
Peter Veres at UAH <>
P. Veres (UAH) reports on behalf of the Fermi GBM Team:

"At 14:15:28.81 UT on 27 July 2018, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 180727A (trigger 554393733 / 180727594)
which was also detected by Swift (Beardmore et al., GCN 23043).
The GBM on-ground location is consistent with the Swift position.

The angle from the Fermi LAT boresight at the GBM trigger time is 46 degrees.

The GBM light curve consists of a single pulse
with a duration (T90) of about 1.1 s (50-300 keV).

The time-averaged spectrum from T0-0.19 s to T0+0.83 s is
best fit by a power law function with an exponential
high-energy cutoff.  The power law index is 0.14 +/- 0.28 and
the cutoff energy, parameterized as Epeak, is 69 +/- 4 keV.

The event fluence (10-1000 keV) in this time interval is
(3.32 +/- 0.18)E-7 erg/cm^2. The 64-msec peak photon flux measured
starting from T0+0.45 s in the 10-1000 keV band
is 7.2 +/- 1.2 ph/s/cm^2.

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