[vsnet-grb-info 17426] Konus-Wind observation of GRB 160101A

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  18838
SUBJECT: Konus-Wind observation of GRB 160101A
DATE:    16/01/07 19:54:28 GMT
FROM:    Dmitry Svinkin at Ioffe Institute  <svinkin at mail.ioffe.ru>

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, intense GRB 160101A
(MAXI detection: Itoh et al., GCN Circ. 18793;
Fermi GBM detection: Veres, GCN Circ. 18796)
triggered Konus-Wind at T0=2631.931 s UT (00:43:51.931).

The burst light curve shows a single pulse
with a total duration of ~4.6 s.
The emission is seen up to ~5 MeV.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB160101_T02631/

As observed by Konus-Wind, the burst
had a fluence of 1.47(-0.17,+0.21)x10^-5 erg/cm2,
and a 64-ms peak flux, measured from T0+0.214 s,
of 1.18(-0.30,+0.35)x10^-5 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 the GRB (Band) model with the following parameters:
the low-energy photon index alpha = -1.19(-0.19,+0.25),
the high energy photon index beta = -2.86(-7.14,+0.38),
the peak energy 143(-19,+20) keV
(chi2 = 103/83 dof).

The spectrum near the maximum count rate
(measured from T0 to T0+0.256 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 = -1.06(-0.23,+0.27)
and Ep = 612(-175,+321) keV (chi2 = 26/41 dof).
Fitting by a GRB (Band) model yields the same alpha and Ep,
and an upper limit on the high energy photon index: beta <-2.0
(chi2 = 26/40 dof).

All the quoted errors are at the 90% confidence level.
All the quoted values are preliminary.