[vsnet-grb-info 19084] Konus-Wind observation of GRB 170207A

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  20629
SUBJECT: Konus-Wind observation of GRB 170207A
DATE:    17/02/08 17:11:32 GMT
FROM:    Dmitry Svinkin at Ioffe Institute  <svinkin at mail.ioffe.ru>

D. Svinkin, S. Golenetskii, R. Aptekar, D. Frederiks, P. Oleynik,
M. Ulanov, A. Tsvetkova, A. Lysenko, A.Kozlova, and T. Cline
on behalf of the Konus-Wind team, report:

The long-duration, very bright GRB 170207A
(IPN triangulation: Svinkin et al, GCN Circ. 20628)
triggered Konus-Wind at T0=78301.73 s UT (21:45:01.730).

The burst light curve shows three multipeaked emission episodes
which started at ~T0-0.3 s and had a total duration of ~42 s.
The emission is seen up to ~10 MeV.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB170207_T78301/

As observed by Konus-Wind, the burst
had a fluence of 7.84(-0.96,+0.85)x10^-5 erg/cm2,
and a 64-ms peak flux, measured from T0+18.016 s,
of 1.50(-0.21,+0.26)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+41.984 s)
is best fit in the 20 keV - 15 MeV range
by the GRB (Band) model with the following parameters:
the low-energy photon index alpha = -0.86(-0.06,+0.06),
the high energy photon index beta = -2.63(-0.84,+0.26),
the peak energy Ep = 394(-33,+42) keV
(chi2 = 106/97 dof)

The spectrum near the maximum count rate
(measured from T0+13.824 to T0+18.944 s)
is best fit in the 20 keV - 15 MeV range
by the GRB (Band) model with the following parameters:
the low-energy photon index alpha = -0.63(-0.08,+0.08),
the high energy photon index beta = -3.60(-6.40,+0.83),
the peak energy Ep = 524(-46,+56) keV
(chi2 = 107/82 dof)

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