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 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/