[vsnet-grb-info 9474] Konus-Wind observation of GRB 100707A

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  10948
SUBJECT: Konus-Wind observation of GRB 100707A
DATE:    10/07/09 10:09:17 GMT
FROM:    Dmitry Frederiks at Ioffe Institute  <fred at mail.ioffe.ru>

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

The very bright long GRB 100707A
(Fermi/GBM trigger 300156400: Wilson-Hodge and Foley, GCN 10944;
localized by IPN: Hurley et al., GCN 10947)
triggered Konus-Wind at T0=2798.855s UT (00:46:38.855)

The burst light curve consists of a single FRED pulse
with a duration of ~100 s.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB100707_T02798/
The periodic dips seen in the 64-ms lc are caused
by the occultation of the Konus detector
by other instrument on board the rotating Wind s/c.

As observed by Konus-Wind the burst
had a fluence of 8.8(+/-0.6)x10-5 erg/cm2,
and a 64-ms peak flux measured from T0+1.344s
of 2.4(+/- 0.2)x10-5 erg/cm2/s
(both in the 20 keV - 2 MeV energy range).

The time-integrated spectrum of the burst
(from T0 to T0+102.144 s) is best fit
in the 20 keV - 2 MeV range by the GRB (Band)
model, for which:
the low-energy photon index alpha = -0.95 (+/-0.15),
the high energy photon index beta = -2.2 (-0.3, +0.2),
the peak energy Ep = 264(-40, +49)keV (chi2 = 43.5/57 dof).

The spectrum at the maximum count rate
(measured from T0+1.280 to T0+1.792 s) is best fit
in the 20 keV - 2 MeV range by the GRB (Band)
model, for which:
the low-energy photon index alpha = +0.3 (-0.3, +0.5),
the high energy photon index beta = -2.4 (-0.5, +0.3),
the peak energy Ep = 383(-82, +80)keV (chi2 = 53.2/57 dof).

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