[vsnet-grb-info 17627] GRB 160223A: Fermi GBM observation

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  19064
SUBJECT: GRB 160223A: Fermi GBM observation
DATE:    16/02/23 21:35:50 GMT
FROM:    Peter Veres at UAH  <veresp at gmail.com>

P Veres (UAH), K Toelge (MPE), C Meegan (UAH)  and C M Hui (MSFC)
report on behalf of the Fermi GBM Team:

"At 01:44:22.39 UT on 23 February 2016, the Fermi Gamma-Ray Burst
Monitor triggered
and located GRB 160223A (trigger 477884666 / 160223072) which was also
detected by the Swift/BAT
(Markwardt et al., GCN 19057). 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 two separate peaks
with a duration (T90) of about 117 s (50-300 keV).
The time-averaged spectrum from T0-6 s to T0+124 s is
best fit by a power law function with an exponential
high-energy cutoff. The power law index is -0.96 +/- 0.06 and
the cutoff energy, parameterized as Epeak, is 308 +/- 30 keV.

The event fluence (10-1000 keV) in this time interval is
(1.46 +/- 0.06)E-5 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+2.7 s in the 10-1000 keV band
is 5.4 +/- 0.2 ph/s/cm^2.

A Band function fits the spectrum equally well
with Epeak= 282 +/- 45 keV, alpha = -0.94 +/- 0.08 and beta = -2.20 +/-
0.23.


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