[vsnet-grb-info 20362] GRB 180305A: Fermi GBM detection

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  22458
SUBJECT: GRB 180305A: Fermi GBM detection
DATE:    18/03/05 17:10:52 GMT
FROM:    Peter Veres at UAH  <veresp at gmail.com>

P. Veres (UAH) and A. von Kienlin (MPE)
report on behalf of the Fermi GBM Team:

"At 09:26:08.66 UT on 05 March 2018, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 180305A (trigger 541934773 / 180305393) which
was also detected by the Fermi LAT (Axelsson et al., GCN 22457).
The GBM on-ground location is consistent with the LAT position.

The angle from the Fermi LAT boresight at the GBM trigger time is 70 degrees.

The GBM light curve consists of a single bright pulse
with a duration (T90) of about 12.5 s (50-300 keV).
The time-averaged spectrum from T0 to T0+24.1 s is best fit by
a Band function with Epeak= 334 +/- 10 keV, alpha = -0.48 +/- 0.02
and beta = 2.29 +/- 0.07.

The event fluence (10-1000 keV) in this time interval is
(3.302 +/- 0.023)E-5 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+3.65 s in the 10-1000 keV band
is 32.2 +/- 0.5 ph/s/cm^2.

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