GCN Circular 12064

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 long GRB 110604A (detected and localized by IPN
and Swift-BAT: Barthelmy et al., GCN 12063
Not found
 
 
)
triggered Konus-Wind at T0=53385.666s UT (14:49:45.666)

The burst light curve consists of several multi-peaked pulses,
a total duration of the burst is ~45 s.
The emission is seen up to ~8 MeV.
The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB110604_T53385/

As observed by Konus-Wind the burst
had a fluence of (3.1 � 0.3)x10-5 erg/cm2,
and a 64-ms peak flux, measured from T0+2.880 s,
of (4.6 � 0.5)x10-6 erg/cm2/s
(both in the 20 keV - 5 MeV energy range).

The time-integrated spectrum of the burst
(from T0 to T0+37.376 s) is best fitted
in the 20 keV - 5 MeV range by the GRB (Band)
model, for which:
the low-energy photon index alpha = -1.10 (-0.08, +0.10),
the high energy photon index beta = -3.2 (<-2.6),
the peak energy Ep = 166(-16, +15) keV,
chi2 = 71.7/76 dof.

The spectrum at the maximum count rate
(measured from T0 to T0+5.376 s) is best fitted
in the 20 keV - 5 MeV range by the GRB (Band)
model, for which:
the low-energy photon index alpha = -0.8 (-0.1, +0.1),
the high energy photon index beta = -3.0 (-2.5, +0.3),
the peak energy Ep = 183(-14, +17) keV,
chi2 = 64.7/70 dof.

Also, both spectra show, in the 2-8 MeV range,
a hint of a weak additional hard spectral component.

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