TITLE: GCN CIRCULAR NUMBER: 18857 SUBJECT: Konus-Wind observation of GRB 160107A DATE: 16/01/13 13:36:22 GMT FROM: Anastasia Tsvetkova at Ioffe Institute S. Golenetskii, R.Aptekar, D. Frederiks, P. Oleynik, M. Ulanov, D. Svinkin, A. Tsvetkova, A. Lysenko, A. Kozlova and T. Cline on behalf of the Konus-Wind team, report: The long-duration GRB 160107A (MAXI/GSC detection: Nakagawa et al., GCN 18839; Fermi GBM observation: Veres & Meegan, GCN 18844; CALET Gamma-Ray Burst Monitor detection: Nakahira et al., GCN 18845) triggered Konus-Wind at T0=80440.646 s UT (22:20:40.646). The burst light curve shows multiple, partly overlapped peaks in the interval from ~T0-40 s to ~T0+110 s. The emission is seen up to ~5 MeV. As observed by Konus-Wind, the burst had a fluence of 2.48(-0.28,+0.54)x10^-5 erg/cm2, and a 64-ms peak energy flux, measured from T0+25.232 s, of 5.86(-1.22,+1.39)x10^-6 erg/cm2/s (both in the 20 keV - 10 MeV energy range). The time-integrated spectrum of the burst (measured from T0 to T0+106.752 s) is best fit in the 20 keV - 5 MeV range by a power law with exponential cutoff model: dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep) with alpha = -1.75(-0.16,+0.18), and Ep = 131(-36,+85) keV (chi2 = 83/77 dof). Fitting by the GRB (Band) model yields the same alpha and Ep, and an upper limit on the high energy photon index: beta < -2.0 (chi2 = 82/76 dof). The spectrum near the peak count rate (measured from T0+24.832 to T0+33.024 s) is best fit in the 20 keV - 3 MeV range by a power law with exponential cutoff model: dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep) with alpha = -1.52(-0.16,+0.18), and Ep = 198(-43,+86) keV (chi2 = 49/68 dof). Fitting by the GRB (Band) model yields the same alpha and Ep, and an upper limit on the high energy photon index: beta < -2.1 (chi2 = 49/67 dof). The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB160107_T80440/ All the quoted errors are at the 90% confidence level. All the quoted values are preliminary.