[vsnet-grb-info 20011] Konus-Wind observation of GRB 171103A (short/hard)

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  22101
SUBJECT: Konus-Wind observation of GRB 171103A (short/hard)
DATE:    17/11/05 20:11:39 GMT
FROM:    Anastasia Tsvetkova at Ioffe Institute  <tsvetkova at mail.ioffe.ru>

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

The short-duration, hard-spectrum, intense GRB 171103A
(Swift detection of a short hard burst: Ukwatta et al., GCN 22095;
Palmer et al., GCN 22099;
Fermi GBM observation: Veres, GCN 22100)
triggered Konus-Wind at T0=83429.176 s UT (23:10:29.176).

The burst light curve shows a single pulse with a total duration of ~0.3 s.
The emission is seen up to ~15 MeV.

As observed by Konus-Wind, the burst
had a fluence of 8.50(-1.47,+1.57)x10^-6 erg/cm2,
and a 16-ms peak energy flux, measured from T0-0.030 s,
of 7.12(-2.18,+2.26)x10^-5 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

The time-integrated spectrum of the burst
(measured from T0 to T0+0.256 s)
is best fit in the 20 keV - 15 MeV range
by a power law with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
with  alpha = -0.76(-0.17,+0.20),
and Ep = 2463(-690,+1054) keV (chi2 = 31/28 dof).
Fitting by the GRB (Band) model yields the same alpha and Ep,
and an upper limit on the high energy photon index:
beta < -1.98 (chi2 = 31/27 dof).

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB171103_T83429/

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