[vsnet-grb-info 1800] Konus-Wind observation of GRB 050717

[GCN Circulars]

TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  3640
SUBJECT: Konus-Wind observation of GRB 050717
DATE:    05/07/18 14:22:55 GMT
FROM:    Dmitry Frederiks at Ioffe Institute  <fred at mail.ioffe.ru>

S. Golenetskii, R.Aptekar, E. Mazets, V. Pal'shin, D. Frederiks, and
T. Cline on behalf of the Konus-Wind team report:

The long hard GRB 050717 (Swift-BAT trigger #146372;
Hurkett et al., GCN 3633, 3636)
triggered Konus-Wind at T0=37857.426s UT (10:30:57.426).
As observed by Konus-Wind it had a steep rise and a long decaying tail.
This tail is seen up to ~50 s after T0.

The burst fluence is ~6.0x10-5 erg/cm2,
peak flux on 64-ms time scale is ~1.2x10-5  erg/cm2 s
(both in the 20 keV - 6 MeV energy range).
The uncertainties in the derived fluence and peak flux are
dominated by uncertainties in high energy part of
the GRB's spectra
(the fluence calculated in 20-350 keV energy range is 1.2x10-5 erg/cm2,
which coincides with the value derived by Swift-BAT)

The time-integrated spectrum (from T0 to T0+51.712 s)
is well fitted (in 20 keV-6 MeV range)
by a power law with exponential cutoff model:
dN/dE ~ E^(-alpha) exp(-E/E0)
with alpha = 1.12 (-0.17, +0.13),
and E0 = 2150 (-1070, +2300)  keV.
The peak energy Ep = 1890 (-760, +1600) keV.
The spectrum can also be fitted by a GRBM (Band) model, but in this
case the high energy photon index beta = -1.71 (-0.95, +0.21)
and only lower limit on Ep can be found: Ep >= 900 keV.

The spectrum of the main peak (from T0 to T0+5.376 s)
is well fitted (in 20 keV-6 MeV range)
by a power law with exponential cutoff model
with alpha = 1.06 ± 0.10,
and E0 = 2470 (-850, +1480)  keV.
The peak energy Ep = 2300 (-670, +1100) keV.
(For GRBM model, beta = -1.73 (-0.33, +0.21)).

All quoted unceratinties are at 90% confidence level.