[vsnet-grb-info 6256] Konus-Wind observation of GRB 080613B

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  7884
SUBJECT: Konus-Wind observation of GRB 080613B
DATE:    08/06/15 15:01:08 GMT
FROM:    Valentin Pal'shin at Ioffe Inst  <val at mail.ioffe.ru>

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

The long GRB 080613B (Swift-BAT trigger
#313954: Markwardt et al., GCN 7873, Ukwatta et al., GCN 7876) triggered 
Konus-Wind at T0=40358.636 s UT (11:12:38.636).

The burst light curve shows a multipeaked structure with a duration of ~30s.

As observed by Konus-Wind the burst
had a fluence of 2.21(-0.38, +0.44)x10^-5 erg/cm2,
and a 256-ms peak flux measured from T0-0.144 s
of 4.76(-1.24, +1.39)x10^-6 erg/cm2/s
(both in the 20 keV - 3 MeV energy range).

The time-integrated spectrum of the burst
(from T0 to T0+33.024 s) is well fitted (in the 20 keV-3 MeV range)
by a power law with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
with alpha = -1.05 +/- 0.18
and Ep = 733(-200, +285) keV (chi2 = 56.6/65 dof).
Fitting by GRBM (Band) model yields the same alpha and Ep,
and only an upper limit on the high energy photon index: beta < -2.05
(chi2 = 56.5/64 dof).

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

The Konus-Wind light curve of this GRB is available
at http://www.ioffe.rssi.ru/LEA/GRBs/GRB080613_T40358/