[vsnet-grb-info 2311] Konus-Wind observation of GRB 051022

[GCN Circulars]

TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  4150
SUBJECT: Konus-Wind observation of GRB 051022
DATE:    05/10/23 15:19:17 GMT
FROM:    Valentin Pal'shin at Ioffe Inst  <val 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 intense GRB 051022 (HETE trigger #3590; Graziani, GCN 4131)
triggered Konus-Wind at T0=47305.298 s UT (13:08:25.298)

The total burst duration is ~200 sec.

The time-integrated spectrum of the GRB (from T0 to T0+197.12 sec)
is well fitted (in the 20 keV - 2 MeV range)
by a power law with exponential cutoff model:
dN/dE ~ E^(-alpha) * exp(-E/E0)
with alpha = 1.176 +/- 0.038
and E0 = 619 (-61, +71) keV (chi^2 = 55/61 dof).
The peak energy Ep = 510 (-33, +37) keV.

This Ep value is significantly larger than 
the Ep=306 (+31, -26) keV derived by HETE (Doty et al., GCN 4145),
while the alpha values are in agreement.
Probably, this discrepancy in Ep is due to the limited 
energy range of the FREGATE.

As observed by Konus-Wind the burst had a fluence 
2.61(-0.11, +0.06)x10^-4 erg/cm2 and
peak flux on 64-ms time scale (1.00 +/- 0.13)x10^-5 erg/cm2/sec
(both in the 20 keV - 2 MeV energy range).

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