GCN Circular 8412
Subject
Konus-Wind observation of GRB 081025
Event
Date
2008-10-26T15:33:49Z (17 years ago)
From
Valentin Pal'shin at Ioffe Inst <val@mail.ioffe.ru>
S. Golenetskii, R. Aptekar, E. Mazets, V. Pal'shin,
D. Frederiks, P. Oleynik, D. Svinkin, M. Ulanov
and T. Cline, on behalf of the Konus-Wind team report:
The long Swift-BATSS GRB 081025 (Copete et al., GCN 8409) triggered
Konus-Wind at T0=30186.316 s UT (08:23:06.316).
The burst light curve shows a multipeaked structure with a total
duration of ~25 s.
As observed by Konus-Wind the burst
had a fluence of 5.37(-0.82, +0.96)x10^-6 erg/cm2,
and a 256-ms peak flux measured from T0-0.224 s
of 8.90(-2.62, +2.75)x10^-7 erg/cm2/s
(both in the 20 keV - 1 MeV energy range).
The time-integrated spectrum of the burst
(from T0 to T0+24.832 s) is well fitted (in the 20 keV-1 MeV range)
by a power law with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
with alpha = -0.67(-0.33, +0.43) ,
and Ep = 222(-46, +81) keV (chi2 = 55.5/60 dof).
Fitting by GRBM (Band) model yields only an upper limit on
the high energy photon index: beta < -2.07.
All the quoted errors are at the 90% confidence level.
The Konus-Wind light curve of this GRB is available
at http://www.ioffe.ru/LEA/GRBs/GRB081025_T30186/