[vsnet-grb-info 18319] Konus-Wind observation of GRB 160802A

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  19767
SUBJECT: Konus-Wind observation of GRB 160802A
DATE:    16/08/04 17:58:30 GMT
FROM:    Anna Kozlova at Ioffe Institute  <ann_kozlova at mail.ioffe.ru>

A. Kozlova, S. Golenetskii, R. Aptekar, D. Frederiks, P. Oleynik,
M. Ulanov, D. Svinkin, A. Tsvetkova, A. Lysenko, and T. Cline
on behalf of the Konus-Wind team, report:

The long-duration bright GRB 160802A
(Fermi GBM observation: Bissaldi, GCN 19754;
Lomonosov BDRG GRBM detection: Panasyuk et al., GCN 19759;
IPN triangulation: Hurley et al., GCN 19766 )
triggered Konus-Wind at T0=22409.945 s UT (06:13:29.945).

The burst light curve shows a multipeaked structure
started at ~T0-0.1 s with a total duration of ~20.0 s.
The emission is seen up to ~3 MeV.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB160802_T22409/

As observed by Konus-Wind, the burst
had a fluence of 8.37(-0.47,+0.50)x10^-5 erg/cm2,
and a 64-ms peak flux, measured from T0+0.976 s,
of 3.27(-0.41,+0.42)x10^-5 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

The time-averaged spectrum of the burst
(measured from T0 to T0+20.224 s)
is best fit in the 20 keV - 3 MeV range
by the GRB (Band) model with the following parameters:
the low-energy photon index alpha = -0.74(-0.05,+0.05),
the high energy photon index beta = -2.43(-0.12,+0.10),
the peak energy Ep = 273(-14,+15) keV
(chi2 = 111/68 dof)

The spectrum near the maximum count rate
(measured from T0+0.768 to T0+1.280 s)
is best fit in the 20 keV - 3 MeV range
by the GRB (Band) model with the following parameters:
the low-energy photon index alpha = -0.14(-0.14,+0.15),
the high energy photon index beta = -2.42(-0.24,+0.16),
the peak energy Ep = 306(-30,+36) keV
(chi2 = 73/51 dof)

All the quoted errors are at the 90% confidence level.
All the quoted values are preliminary.