[vsnet-grb-info 15057] Konus-Wind observation of GRB 140604A

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  16351
SUBJECT: Konus-Wind observation of GRB 140604A
DATE:    14/06/05 15:35:03 GMT
FROM:    Valentin Pal'shin at Ioffe Inst  <val at mail.ioffe.ru>

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

The short-duration, hard spectrum, bright GRB 140604A (Golenetskii et 
al., GCN ) triggered Konus-Wind at T0=17415.447 s UT (04:50:15.447).
The burst light curve shows several peaks with a total duration of ~1s. 
The emission is seen up to ~3 MeV.

As observed by Konus-Wind, the burst had a fluence of
7.2(-1.8,+2.4)x10^-6 erg/cm2, and a 16-ms peak flux, measured from 
T0+0.592 s, of 2.55(-0.65,+0.89)x10^-5 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

The time-integrated spectrum of the burst (measured from T0 to T0+8.448 
s) is best fit in the 20 keV - 4 MeV range
by a power law with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
with  alpha = -0.54(-0.32,+0.43),
and Ep = 795(-236,+414) keV (chi2 = 62/68 dof).
Fitting by a GRB (Band) model yields the same alpha and Ep,
and an upper limit on the high energy photon index: beta < -1.7 (chi2 = 
62/67 dof).

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB140604_T17415/

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