[vsnet-grb-info 10211] Konus-Wind observation of GRB 110205A

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  11659
SUBJECT: Konus-Wind observation of GRB 110205A
DATE:    11/02/07 11:34:21 GMT
FROM:    Valentin Pal'shin at Ioffe Inst  <val at mail.ioffe.ru>

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

The long GRB 110205A (Swift-BAT trigger #444643: Beardmore et al., GCN
11629; Markwardt et al., GCN 11646) was detected by Konus-Wind in the
waiting mode.

The burst light curve shows a multipeaked pulse started at ~T0(BAT) with 
a total duration of ~330 s. There is a weak pulse at ~T0(BAT)-1360 s 
(seen by the same detector which observed GRB 110205A; the detection 
significance is ~4.5 sigma in the G1+G2 (20-360 keV) band; the pulse 
duration is ~25 s), which might be a burst precursor. There is a hint of 
a weak soft tail seen up to ~T0+1200 s.

As observed by Konus-Wind, the burst had a fluence of (3.66 +/- 
0.35)x10^-5 erg/cm2 and a 3-s peak flux measured from T0+211.6 s
of (5.1 +/- 0.7)x10^-7 erg/cm2/s (both in the 20 - 1200 keV energy range).

Modeling the K-W 3-channel time-integrated spectrum (from T0 s to
T0+330 s) by a power law with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
yields alpha = -1.52 +/- 0.14, and Ep = 222 +/- 74 keV.

Assuming z = 2.22 (Cenko & Hora, GCN 11638; Vreeswijk et al. GCN 11640) 
and a standard cosmology model with H_0 = 71 km/s/Mpc, Omega_M = 0.27, 
Omega_Lambda = 0.73, the isotropic energy release E_iso is (1.36 +/- 
0.13)x10^54 erg, the peak luminosity (L_iso)_max is (5.9 +/- 0.8)x10^51 
erg/s, and Ep_rest is 715 +/- 238 keV.

All the quoted errors are estimated at the 1 sigma confidence level.

The K-W light curve of this burst is available at
http://www.ioffe.rssi.ru/LEA/GRBs/GRB110205A/