TITLE: GCN CIRCULAR NUMBER: 13103 SUBJECT: Konus-Wind observation of GRB 120323A DATE: 12/03/25 12:28:28 GMT FROM: Dmitry Frederiks at Ioffe Institute S. Golenetskii, R.Aptekar, D. Frederiks, E. Mazets, V. Pal'shin, P. Oleynik, M. Ulanov, D. Svinkin, and T. Cline on behalf of the Konus-Wind team, report: The short very intense GRB 120323A (Fermi/GBM detection: Gruber & Connaughton, GCN 13099; IPN localization: Golenetskii at al., GCN 13102) triggered Konus-Wind at T0=43815.970s UT (12:10:15.970) The light curve shows a double-headed FRED-like structure. A total duration of the burst is ~0.5 s. The emission is seen up to ~8 MeV. The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB120323_T43815/ A spectral lag between hard G3(300-1400 keV) and soft G1(22-80 keV) instrument's light curves is estimated to (-0.002 +/- 0.004) s. As observed by Konus-Wind the burst had a fluence of 1.03(-0.07,+0.07)x10-5 erg/cm2, and a 16-ms peak flux, measured from T0+0.016 s, of 7.2(-0.9,+0.9)x10-5 erg/cm2/s (both in the 20 keV - 10 MeV energy range). The spectrum of the burst (measured from T0 to T0+0.256 s) is well fit in the 20 keV - 10 MeV range by a power law with exponential cutoff model, for which alpha = -1.57 (-0.07, +0.07), and Ep = 331(-50, +64) keV, chi2 = 45.8/42 dof. Fitting this spectrum with the GRB (Band) function gives an equally good result with the following model parameters: the low-energy photon index alpha = -1.56 (-0.07, +0.09), the high energy photon index beta = -2.9 (<-2.4), the peak energy Ep = 317(-76, +68) keV, chi2 = 44.3/41 dof. All the quoted results are preliminary. All the quoted errors are at the 90% confidence level.