[vsnet-grb-info 19688] Konus-Wind observation of GRB 170805B

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  21442
SUBJECT: Konus-Wind observation of GRB 170805B
DATE:    17/08/10 11:41:06 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 170805B
(IPN triangulation: Hurley et al., GCN 21428)
triggered Konus-Wind at T0=51527.165 s UT (14:18:47.165).

The burst light curve shows a single pulse
which starts at T0-32 ms and has a total duration of ~0.2 s.

As observed by Konus-Wind, the burst
had a fluence of 1.23(-0.21,+0.46)x10^-6 erg/cm2,
and a 16-ms peak flux, measured from T0-0.008 s,
of 2.25(-0.47,+0.89)x10^-5 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

Since the most intense part of the burst was detected before
the trigger, the spectral analysis was performed using
the KW 3-channel light curve data.

Modeling the KW 3-channel time-integrated spectrum
(from T0-0.032 s to T0+0.146 s)
by a power law with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
yields alpha = -0.97 (-0.15,+0.19), and Ep = 720 (-192,+474) keV.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB170805_T51527/

All the quoted errors are at the 68% confidence level.
All the quoted values are preliminary.