[vsnet-grb-info 17619] GRB 160221A: Fermi GBM observation

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  19056
SUBJECT: GRB 160221A: Fermi GBM observation
DATE:    16/02/22 17:38:49 GMT
FROM:    C. Michelle Hui at MSFC/Fermi-GBM  <c.m.hui at nasa.gov>

C. M. Hui (NASA/MSFC) and E. Bissaldi (Politecnico & INFN Bari)
report on behalf of the Fermi GBM Team:

"At 23:49:45.22 UT on 21 February 2016, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 160221A (trigger 477791389 / 160221993),
which was also detected by INTEGRAL (Mereghetti et al., GCN 19046).
The GBM on-ground location is consistent with the INTEGRAL position.

The angle from the Fermi LAT boresight at the GBM trigger time is 58 degrees.

The GBM light curve consists of a single pulse
with a duration (T90) of about 15 s (50-300 keV).
The time-averaged spectrum from T0-1.5 s to T0+5.6 s is
best fit by a power law function with an exponential
high-energy cutoff.  The power law index is -1.15 +/- 0.16 and
the cutoff energy, parameterized as Epeak, is 67 +/- 7 keV.

The event fluence (10-1000 keV) in this time interval is
(1.55 +/- 0.14)E-06 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+2.2 s in the 10-1000 keV band
is 4.0 +/- 0.3 ph/s/cm^2.


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