[vsnet-grb-info 15786] Konus-Wind observation of GRB 141118A

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  17074
SUBJECT: Konus-Wind observation of GRB 141118A
DATE:    14/11/20 13:58:43 GMT
FROM:    Dmitry Frederiks at Ioffe Institute  <fred at mail.ioffe.ru>

S. Golenetskii, R.Aptekar, D. Frederiks, V. Pal'shin, P. Oleynik,
M. Ulanov, D. Svinkin, A. Tsvetkova, A.Lyssenko, and T. Cline
on behalf of the Konus-Wind team, report:

A long-duration GRB 141118A (IPN triangulation: Hurley et al., GCN 17073)
triggered Konus-Wind at T0=58548.540 s UT (16:15:48.540).

The KW light curve shows a single emission episode lasting from ~T0-0.5 s
to ~T0+5 s. The emission in this episode is visible up to ~2 MeV.

As observed by Konus-Wind, the burst had a fluence
of 2.3(-0.5,+1.4)x10^-6 erg/cm2, and a 64-ms peak flux,
measured from T0, of 1.6(-0.4,+1.0)x10^-6 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

The time-averaged spectrum (measured from T0 to T0+8.448 s)
is best fit in the 20 keV - 15 MeV range
by the cutoff power law with the following model parameters:
the photon index alpha = -1.14(-0.67,+0.89),
and the peak energy Ep = 165(-55,+198) keV,
chi2 = 95/97 dof.
Fitting this spectrum with the Band model yields the same
values of alpha and Ep and an upper limit on beta of -2.0

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB141118_T58548/

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