[vsnet-grb-info 11303] Konus-Wind observation of GRB 111222A

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  12715
SUBJECT: Konus-Wind observation of GRB 111222A
DATE:    11/12/23 18:25:13 GMT
FROM:    Dmitry Frederiks at Ioffe Institute  <fred at mail.ioffe.ru>

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

The short hard intense GRB 111222A
(localized by IPN: Hurley et al., GCN 12714)
triggered Konus-Wind at T0=53515.918s UT (14:51:55.918)

The light curve consists of a single multi-peaked pulse with
a total duration of ~300 ms.
The emission is seen up to ~3 MeV.
The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB111222_T53515/

As observed by Konus-Wind the burst
had a fluence of (7.2 ± 0.7)x10-6 erg/cm2,
and a 16-ms peak flux, measured from T0 s,
of (5.1 ± 0.7)x10-5 erg/cm2/s
(both in the 20 keV - 3 MeV energy range).

The spectrum of the burst (measured from T0 to T0+0.256 s)
is best fitted in the 20 keV - 3 MeV range
by a power law with exponential cutoff model, for which
alpha = -0.35 (-0.13, +0.14),
and Ep = 762(-89, +101) keV,
chi2 = 51.1/45 dof.

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