[vsnet-grb-info 2602] Konus-Wind observation of GRB 060105

[GCN Circulars]

TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  4439
SUBJECT: Konus-Wind observation of GRB 060105
DATE:    06/01/06 13:10:21 GMT
FROM:    Valentin Pal'shin at Ioffe Inst  <val at mail.ioffe.ru>

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

The GRB 060105 (Swift-BAT trigger #175942;
Ziaeepour et al., GCN 4429; Markwardt et al., GCN 4435)
triggered Konus-Wind at T0=24544.371 s UT (06:49:04.371).

The Konus-Wind light curve consists of three main
multipeaked pulses with a total duration of ~60 sec.

As observed by Konus-Wind the burst had
a fluence of 7.86(-0.37,+0.19)x10^-5 erg/cm2 and
peak flux on 256 msec time scale 6.55(-0.45,+0.19)x10^-6 erg/cm2/sec
(both in the 20 keV - 2 MeV energy range).

The time-integrated spectrum of the GRB (from T0 to T0+58.880 sec)
is well fitted (in the 20 keV - 2 MeV range)
by a power law with exponential cutoff model:
dN/dE ~ E^(-alpha) * exp(-E*(2-alpha)/Ep)
with alpha = 0.827(-0.044,+0.042)
and Ep = 424(-22, +25) keV (chi2 = 63/62dof).
It can also be fitted by GRBM (Band) model for which:
the low-energy photon index is alpha = -0.790 (-0.052,+0.067),
the high energy photon index beta = -2.70(-0.73, +0.35),
the break energy E0 = 327 (-46, +40) keV (chi2 = 58/61dof).

The spectrum integrated over the most intense part of the GRB
(from T0+16.64 to T0+29.184 sec) is well fitted
(in the 20 keV - 2 MeV range)
by a power law with exponential cutoff model:
dN/dE ~ E^(-alpha) * exp(-E*(2-alpha)/Ep)
with alpha = 0.571(-0.060,+0.057)
and Ep = 549(-31, +34) keV (chi2 = 73/62dof).

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