[vsnet-grb-info 7468] Konus-Wind observation of GRB 090323

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  9030
SUBJECT: Konus-Wind observation of GRB 090323
DATE:    09/03/24 12:25:07 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 090323 (Fermi-GBM trigger 259459364 / 090323002) localized 
by Fermi-LAT (Ohno et al., GCN 9021; the LAT localization was confirmed 
by the IPN triangulation: Hurley et al., GCN 9023) triggered Konus-Wind 
at T0=174.632 s UT (00:02:54.632).

The burst light curve shows several pulses with a total duration of
~160 s, followed by a weak tail marginally seen up to ~T0+300 s in all 
energy bands.

As observed by Konus-Wind the burst
had a fluence of 2.02(-0.25, +0.28)x10^-4 erg/cm2,
and a 256-ms peak flux measured from T0+58.240 s
of 5.96(-1.06, +1.09)x10^-6 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

The time-integrated spectrum of the burst
(from T0 to T0+145.664 s) can be fitted (in the 20 keV - 10 MeV
range) by GRB (Band) model for which:
the low-energy photon index alpha = -0.96(-0.09, +0.12),
the high energy photon index beta = -2.09(-0.22, +0.16),
the peak energy Ep = 416(-73, +76) keV (chi2 = 104.0/89 dof).

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

Assuming z = 3.6 (Chornock et al., GCN 9028)
and a standard cosmology model with H_0 = 70 km/s/Mpc, Omega_M = 0.27,
Omega_\Lambda = 0.73, the isotropic energy release E_iso ~5.6x10^54 erg,
the peak luminosity (L_iso)_max ~ 7.6x10^53 erg/s, and Ep_rest ~1900keV.

The Konus-Wind light curve of this GRB is available
at http://www.ioffe.ru/LEA/GRBs/GRB090323_T00174/