GCN Circular 4150
Subject
Konus-Wind observation of GRB 051022
Event
Date
2005-10-23T15:19:17Z (20 years ago)
From
Valentin Pal'shin at Ioffe Inst <val@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.