A. Kozlova, S. Golenetskii, R. Aptekar, D. Frederiks,
P. Oleynik, M. Ulanov, D. Svinkin, A. Tsvetkova, A. Lysenko,
and T. Cline on behalf of the Konus-Wind team, report:
The long-duration GRB 160216A (Swift-BAT trigger #673978:
Troja et al., GCN Circ. 19014)
triggered Konus-Wind at T0=69030.129 s UT (19:10:30.129).
The burst light curve shows a double-peaked structure
started at ~T0-0.3 s with a total duration (80-1400 keV) of ~3.6 s.
The emission is seen up to ~4 MeV.
As observed by Konus-Wind, the burst
had a fluence of 3.05(-0.35,+0.39)x10^-6 erg/cm2,
and a 64-ms peak flux, measured from T0+2.864 s,
of 2.62(-0.70,+0.71)x10^-6 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).
The time-averaged spectrum of the burst
(measured from T0 to T0+8.448 s)
is best fit in the 20 keV - 10 MeV range
by a power law with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
with alpha = -0.66 (-0.31,+0.36)
and Ep = 140 (-18,+25) keV (chi2 = 91/87 dof).
Fitting by a GRB (Band) model yields the same alpha and Ep,
and an upper limit on the high energy photon index: beta < -3.0
(chi2 = 91/86 dof)
The Konus-Wind light curve of this GRB is available at
Another long-duration GRB 160216B was detected by Konus-Wind
in the same trigger record at ~T0+150 s. This second burst was
also detected by Fermi-GBM, trigger #477342778.The KW ecliptic
latitude response for GRB 160216B is consistent with the GBM
localization and inconsistent with the BAT localization
of GRB 160216A.
All the quoted errors are at the 90% confidence level.
All the quoted values are preliminary.