[vsnet-grb-info 16244] GRB 150301B: Fermi GBM detection

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  17525
SUBJECT: GRB 150301B: Fermi GBM detection
DATE:    15/03/02 05:26:50 GMT
FROM:    Eric Burns at U of Alabama  <eb0016 at uah.edu>

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

"At 19:38:04.51 UT on 01 March 2015, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 150301B (trigger 446931487/150301818)
which was also detected by the Swift/BAT (Lien et al. 2015, GCN 17515).
The GBM on-ground location is consistent with the Swift position.
The angle from the Fermi LAT boresight is 39 degrees.

The GBM light curve consists of one main peak
with a duration (T90) of about 13 s (50-300 keV).
The time-averaged spectrum from T0-2.560 s to T0+13.824 s is
best fit by a power law function with an exponential
high-energy cutoff.  The power law index is -1.2 +/- 0.1 and
the cutoff energy, parameterized as Epeak, is 256 +/- 32 keV.
A Band function fits the spectrum equally well with
Epeak= 180 +/- 38 keV, alpha = -1.1 +/- 0.1 and beta = -2.0 +/- 0.2.

The event fluence (10-1000 keV) in this time interval is
(4.4 +/- 0.2)E-06 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+2.560 s in the 10-1000 keV band
is 4.5 +/- 0.2 ph/s/cm^2.

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