[vsnet-grb-info 20854] GRB 180715A: Fermi GBM detection

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  22952
SUBJECT: GRB 180715A: Fermi GBM detection
DATE:    18/07/16 04:35:23 GMT
FROM:    Rachel Hamburg at UAH  <rkh0007 at uah.edu>

R. Hamburg (UAH) and C. Meegan (UAH)
report on behalf of the Fermi GBM Team:

"At 18:07:05.06 UT on 15 July 2018, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 180715A (trigger 553370830 / 180715755)
which was also detected by the Swift/BAT (Ukwatta et al. 2018, GCN 22947).
The GBM on-ground location is consistent with the Swift position.

The angle from the Fermi LAT boresight at the GBM trigger time is 75
degrees.

The GBM light curve shows a single structured peak
with a duration (T90) of about 0.7 s (50-300 keV).
The time-averaged spectrum from T0-0.19 to T+0.51 s is
adequately fit by a power law function with an exponential
high-energy cutoff.  The power law index is -0.14 +/- 0.21 and
the cutoff energy, parameterized as Epeak, is 852 +/- 182 keV.

The event fluence (10-1000 keV) in this time interval is
(1.7 +/- 0.1)E-06 erg/cm^2. The 64-ms peak photon flux measured
starting from T0-0.064s in the 10-1000 keV band
is 8.4 +/- 1.3 ph/s/cm^2.

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