[vsnet-grb-info 2191] Konus-Wind observation of GRB 050922C

[GCN Circulars]

TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  4030
SUBJECT: Konus-Wind observation of GRB 050922C
DATE:    05/09/23 16:05:24 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 050922C (Swift-BAT trigger #156467; 
Norris et al., GCN 4013, Krimm et al., GCN 4020)
triggered Konus-Wind at T0=71754.480 s  UT (19:55:54.480).
As observed by Konus-Wind it had a duration of ~5 s,
fluence (7.3 +/- 0.5)10-6 erg/cm2,
peak flux on 128-ms time scale (4.5 +/- 0.7)10-6  erg/cm2/s
(both in the 20 keV - 2 MeV energy range).

The time-integrated spectrum of the GRB
(from T0 to T0+8.448 s) is well fitted (in the 20 keV - 2 MeV range)
by a power law model with photon index 1.55 +/- 0.07.
The spectrum does not demonstrate an exponential cutoff
with E0 ~100 keV reported by HETE Fregate (Crew et al., GCN 4021).

Assuming z = 2.17 (Jakobsson et al., GCN 4017) and a standard cosmology
model with H_0 = 70 km/s/Mpc, Omega_M = 0.3, Omega_\Lambda = 0.7,
the isotropic energy release is E_iso ~8.1x10^52 erg,
the maximum luminosity is (L_iso)_max ~1.6x10^53 erg/s.