[vsnet-grb-info 18219] Konus-Wind observation of GRB 160702A (short/hard)

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  19667
SUBJECT: Konus-Wind observation of GRB 160702A (short/hard)
DATE:    16/07/08 20:30:03 GMT
FROM:    Dmitry Frederiks at Ioffe Institute  <fred at mail.ioffe.ru>

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

The short GRB 160702A (IPN triangulation: Hurley et al., GCN 19666)
triggered Konus-Wind at T0=44544.054 s UT (12:22:24.054).

The light curve shows a short, hard pulse with a total duration
of ~200 ms.
The emission is seen up to ~5 MeV.

As observed by Konus-Wind, the burst had a fluence of
(2.5 ± 0.7)x10^-6 erg/cm2 and a 16-ms peak energy flux,
measured from T0-0.016, of (3.0 ± 0.4)x10^-5 erg/cm2
(both in the 20 keV - 10 MeV energy range).

The spectrum of the burst (measured from T0 to T0+0.128 s)
is best fit in the 20 keV - 10 MeV range by a cutoff power-law
(CPL) function with the following model parameters:
the photon index alpha = -0.28(-0.35,+0.48),
and the peak energy Ep = 782(-186,+308) keV,
chi2 = 32.3/31 dof.
Fitting this spectrum with the GRB (Band) function yields
the same alpha and Ep with only an upper limit on beta of -2.1,
chi2 = 31.9/30 dof.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB160702_T44544/

All the quoted errors are estimated at the 90% confidence level.
All the presented results are preliminary.