[vsnet-grb-info 14114] Konus-Wind observation of GRB 131031A

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  15428
SUBJECT: Konus-Wind observation of GRB 131031A
DATE:    13/11/01 09:21:25 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 long-duration GRB 131031A (Cummings, GCN 15421)
triggered Konus-Wind at T0=41619.496 s UT (11:33:39.496).

The burst light curve shows a multi-peaked structure from
~T0-0.5 s till ~T0+6 s.
The emission is seen up to ~7 MeV.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB131031_T41619/

As observed by Konus-Wind, the burst
had a fluence of (4.8 ± 1.2)x10-6 erg/cm2,
and a 64-ms peak flux, measured from T0+0.064 s,
of (3.8 ± 0.5)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 a simple power law with the photon index 2.09 ± 0.15,
chi2 = 82.5/99 dof.

The spectrum at the maximum count rate (measured from T0 to T0+0.256 s)
is best fit in the 20 keV - 15 MeV range
by a simple power law with the photon index 1.96 ± 0.18,
chi2 = 51.3/72 dof.


All the quoted values are preliminary.