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 short-duration, hard-spectrum GRB 160111A
(IPN triangulation: Golenetskii et al., GCN 18864)
triggered Konus-Wind at 26526.639 s UT (07:22:06.639).
The KW light curve shows a single pulse with a duration of ~0.3 s.
The emission is visible up to ~5 MeV.
The Konus-Wind light curve of this GRB is available at
As observed by Konus-Wind, the burst had a fluence
of 2.4(-0.8,+1.0)x10^-6 erg/cm2, and a 16-ms peak flux,
measured from T0, of 9.7(-3.1,+4.1)x10^-6 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).
The spectrum of the burst (measured from T0 to T0+0.128 s)
is best fit in the 20 keV - 10 MeV range
by the cutoff power law with the following model parameters:
the photon index alpha = -0.06(-0.55,+0.84),
and the peak energy Ep = 682(-222,+367) keV,
chi2 = 15.6/19 dof.
Fitting this spectrum with the GRB (Band) function yields
the following model parameters:
the low-energy photon index alpha = -0.13 (-0.11,+0.08),
the high energy photon index beta < -2.35 (upper limit),
the peak energy Ep = 725 (-267, +321) keV,
chi2 = 15.7/18 dof.
All the quoted errors are at the 90% confidence level.
All the quoted values are preliminary.