GCN Circular 17807
Subject
GRB 150510A: Fermi GBM detection
Date
2015-05-10T17:22:58Z (9 years ago)
From
Eric Burns at U of Alabama <eb0016@uah.edu>
E. Burns (UAH) and C. Meegan (UAH)
report on behalf of the Fermi GBM Team:
"At 03:19:53.74 UT on 10 May 2015, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 150510A (trigger 452920796 / 150510139),
which was also detected by the Fermi LAT (Vianello et al. 2015,
GCN 17805). The GBM on-ground location is marginally consistent
with the LAT position.
The angle of the burst direction to the Fermi LAT boresight was
55 degrees. The trigger resulted in an Autonomous Repoint Request
(ARR) that was accepted and the spacecraft slewed to the GBM
in-flight location.
The GBM light curve shows a FRED profile
with a duration (T90) of about 52 s (50-300 keV).
The time-averaged spectrum from T0+0.256 s to T0+52.480 s is
best fit by a power law function with an exponential
high-energy cutoff. The power law index is -1.04 +/- 0.01 and
the cutoff energy, parameterized as Epeak, is 1651 +/- 58 keV.
The event fluence (10-1000 keV) in this time interval is
(9.32 +/- 0.05)E-05 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+0.064 s in the 10-1000 keV band
is 32.0 +/- 0.3 ph/s/cm^2.
The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."