[vsnet-grb-info 20031] Konus-Wind observation of GRB 171108A

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  22119
SUBJECT: Konus-Wind observation of GRB 171108A
DATE:    17/11/13 19:17:41 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, soft-spectrum GRB 171108A
(Fermi GBM detection: Hamburg et al., GCN 22112;
IPN triangulation: Svinkin et al., GCN 22117)
triggered Konus-Wind at T0=56686.93 s UT (15:44:46.930).

The burst light curve shows a single pulse
which starts at T0-22 ms and has a total duration of ~30 ms.

As observed by Konus-Wind, the burst
had a fluence of 2.73(-0.38,+0.48)x10^-7 erg/cm2,
and a 16-ms peak flux, measured from T0-0.016 s,
of 1.25(-0.23,+0.27)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 T0-0.022 s to T0+0.008 s)
by a power law with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
yields alpha = 0.86 (-1.20,+4.43), and Ep = 115 (-20,+30) keV.

Fitting this spectrum by a blackbody function
yields kT = 26.6 (-3.3, +4.3) keV.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB171108_T56686/

The burst is not seen in the waiting mode data.

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