[vsnet-grb-info 19158] GRB 170228A: Fermi GBM observation

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  20786
SUBJECT: GRB 170228A: Fermi GBM observation
DATE:    17/03/01 16:32:05 GMT
FROM:    Peter Veres at UAH  <veresp at gmail.com>

P. Veres, M. Stanbro and C. Meegan (UAH)
report on behalf of the Fermi GBM Team:

"At 19:03:00.71 UT on 28 February 2017, the Fermi Gamma-Ray Burst
Monitor triggered and located GRB 170228A (trigger 510001385 /
170228794) which was also detected by Fermi/LAT (Bissaldi et al., GCN
20785). The GBM on-ground location is consistent with the LAT
position.


The GBM light curve shows a single pulse followed by weaker emission
with a duration (T90) of about 62 s (50-300 keV).
The time-averaged spectrum from T0 to T0 + 18.8 s is
best fit by a Band function with Epeak = 755 +/- 76 keV,
alpha = -0.50 +/- 0.07, and beta = -2.35 +/- 0.17.

The event fluence (10-1000 keV) in this time interval is
(2.23 +/- 0.06)E-5 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+1.0 s in the 10-1000 keV band
is 10.2 +/- 0.2 ph/s/cm^2.


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