[vsnet-grb-info 18337] Konus-Wind observation of GRB 160806A

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  19785
SUBJECT: Konus-Wind observation of GRB 160806A
DATE:    16/08/09 13:29:03 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 short-duration GRB 160806A
(IPN triangulation: Hurley et al., GCN 19784)
triggered Konus-Wind at T0=50460.639 s UT (14:01:00.639).

The burst light curve shows a single pulse
which starts at ~T0-0.5 s and has a total duration of ~1.0 s.
The emission is seen up to ~8 MeV.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB160806_T50460/

As observed by Konus-Wind, the burst
had a fluence of 1.16(-0.23,+0.49)x10^-6 erg/cm2,
and a 16-ms peak flux, measured from T0-0.026 s,
of 5.98(-3.46,+4.98)x10^-6 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

The spectrum of the burst
(measured from T0 to T0+0.256 s)
is well fit in the 20 keV - 8 MeV range
by a power law with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
with  alpha = -1.00 (-0.51,+0.80)
and Ep = 219 (-76,+395) keV (chi2 = 43/33 dof).
Fitting by a GRB (Band) model yields alpha = -0.63 (-0.65,+1.00),
Ep = 171 (-59,+154) keV, and an upper limit on the high energy
photon index: beta < -1.8 (chi2 = 40/32 dof)

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