[vsnet-grb-info 14235] Konus-Wind observation of GRB 131125A

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  15549
SUBJECT: Konus-Wind observation of GRB 131125A
DATE:    13/11/29 15:52:50 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, and T. Cline, on behalf
of the Konus-Wind team, report:

The short-duration, hard-spectrum GRB 131125A
(IPN Triangulation: Golenetskii et al. GCN 15546)
triggered Konus-Wind at T0=59572.927 s UT (16:32:52.927).

The burst duration is ~0.5 s.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB131125_T59572/

As observed by Konus-Wind, the burst
had a fluence of (1.3 ± 0.2)x10-6 erg/cm2,
and a 64-ms peak flux, measured from T0-0.064,
of (5.7 ± 1.2)x10-6 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

The 3-channel time-integrated spectrum
(measured from T0-0.448 to T0+0.064 s)
can be modeled, in the 22 keV - 1.3 MeV range,
by the cutoff power law with the following model parameters:
the photon index alpha = 0.00 ± 0.13,
and the peak energy Ep = 638 ± 62 keV.

The 3-channel spectrum at the maximum count rate
(measured from T0-0.064 s to T0)
can be modeled, in the 22 keV - 1.3 MeV range,
by the cutoff power law with the following model parameters:
the photon index alpha = +0.2 ± 0.3,
and the peak energy Ep = 665 ± 113 keV.

All the quoted results are preliminary.