GCN Circular 16658
Subject
GRB 140801A: Fermi GBM observation
Date
2014-08-02T05:37:24Z (10 years ago)
From
Veronique Pelassa at UAH <vero.pelassa@gmail.com>
V. Pelassa (UAH) reports on behalf of the Fermi GBM Team:
"At 18:59:53.26 UT on 1 August 2014, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 140801A (trigger 428612396 / 140801792).
An optical transient was detected by the MASTER II robotic telescope
(Lipunov et al. 2014, GCN 16653). The GBM on-ground location is
consistent with the OT location, which angle from the Fermi LAT
boresight is 80 degrees.
The GBM light curve consists of two bright pulses followed by a
short tail, with a duration (T90) of about 7 s (50-300 keV).
The time-averaged spectrum from T0-2.048 s to T0+12.288 s is
well fit by a power law function with an exponential
high-energy cutoff. The power law index is -0.42 +/- 0.03 and
the cutoff energy, parameterized as Epeak, is 125 +/- 2 keV
(Castor-statistics 697.99 for 610 d.o.f.).
A Band function fits the spectrum equally well (Castor-statistics
695.14 for 609 d.o.f.) with Epeak= 122 +/- 3 keV,
alpha = -0.40 +/- 0.04 and beta = -3.6 +/- 0.4.
The event fluence (10-1000 keV) in this time interval is
(1.22 +/- 0.01)E-05 erg/cm^2. The 1.024-sec peak photon flux measured
starting from T0+0.832 s in the 10-1000 keV band
is 22.6 +/- 0.4 ph/s/cm^2.
The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."