[vsnet-grb-info 13767] Konus-Wind observation of GRB 130804A

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  15081
SUBJECT: Konus-Wind observation of GRB 130804A
DATE:    13/08/07 10:41:35 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 bright, short-duration GRB 130804A
(Fermi-GBM detection: Yu, Goldstein, and Pelassa, GCN 15070;
IPN triangulation: Golenetskii at al., GCN 15075)
triggered Konus-Wind at T0=1997.053 s UT (00:33:17.053).

The burst light curve from ~T0-0.2 s to ~T0+1 s shows three major pulses
with the brightest, hard-spectrum pulse peaked at ~T0.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB130804_T01997/

As observed by Konus-Wind, the burst
had a fluence of (1.8 ± 0.2)x10-6 erg/cm2,
and a 16-ms peak flux, measured from T0,
of (3.4 ± 0.3)x10-5 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

The 3-channel time-integrated spectrum
(measured from T0-0.256 to T0+1.024 s)
can be modeled, in the 25 keV - 1.5 MeV range,
by the cutoff power law with the following model parameters:
the photon index alpha = -0.94 ± 0.06,
and the peak energy Ep = 434 ± 37 keV.

All the quoted results are preliminary.