TITLE: GCN CIRCULAR NUMBER: 16035 SUBJECT: Konus-Wind observation of GRB 140323A DATE: 14/03/24 13:39:28 GMT FROM: Dmitry Frederiks at Ioffe Institute S. Golenetskii, R.Aptekar, D. Frederiks, V. Pal'shin, P. Oleynik, M. Ulanov, D. Svinkin, A. Tsvetkova, and T. Cline on behalf of the Konus-Wind team, report: A long-duration GRB 140323A (Swift-BAT trigger 592916: Troja et al., GCN 16027; Sakamoto et al., GCN 16029; Fermi-GBM detection: Yu & von Kienlin, GCN 16032; Fermi-LAT detection: Vianello et al., GCN 16034) triggered Konus-Wind at T0=37392.356 s UT (10:23:12.356). The burst light curve shows multiple peaks in two major bursting episodes. A total duration of the burst is ~130 s. The emission is seen up to ~10 MeV. As observed by Konus-Wind, the burst had a fluence of 3.1(-0.4,+0.7)x10^-5 erg/cm2, and a 64-ms peak flux, measured from T0+5.376 s, of 3.2(-0.6,+0.7)x10^-6 erg/cm2/s (both in the 20 keV - 10 MeV energy range). The time-averaged spectrum (measured from T0 to T0+106.752 s) is best fit in the 20 keV - 18 MeV range by the GRB (Band) function with the following model parameters: the low-energy photon index alpha = -1.09 (-0.15,+0.31), the high energy photon index beta = -3.0 (-7.0,+0.6), the peak energy Ep = 127 (-24,+16) keV, chi2 = 93.4/97 dof. The spectrum near the maximum count rate (measured from T0 to T0+8.448 s) is best fit in the 20 keV - 18 MeV range by the GRB (Band) function with the following model parameters: the low-energy photon index alpha = -0.79 (-0.18,+0.20), the high energy photon index beta = -2.7 (-6.0,+0.3), the peak energy Ep = 184 (-24,+31) keV, chi2 = 96.8/87 dof. The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB140323_T37392/ All the quoted errors are at the 90% confidence level. All the quoted values are preliminary.