[vsnet-grb-info 8146] Konus-Wind and Konus-RF observations of GRB 090715B

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  9679
SUBJECT: Konus-Wind and Konus-RF observations of GRB 090715B
DATE:    09/07/16 12:52:47 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, and D. Svinkin on behalf of
the Konus-Wind and Konus-RF teams, and
T. Cline on behalf of the Konus-Wind team, report:

The long GRB 090715B (Vetere et al., GCN 9668)
triggered Konus-Wind at T0=75799.008 s UT (21:03:19.008),
and Konus-RF instrument onboard CORONAS-PHOTON s/c
at T0(KRF)=75798.895 s UT (21:03:18.895).

The burst had a multi-peaked structure with a duration of ~100 s.
The Konus-Wind light curves of this GRB are available at
http://www.ioffe.ru/LEA/GRBs/GRB090715_T75799/

As observed by Konus-Wind, the burst had a fluence
of 9.3(-1.1,+1.5)x10-6 erg/cm2,
and a 256-ms peak flux, measured from T0+4.912 s,
of 9.0(-2.5,+2.5)x10-7 erg/cm2/s
(both in the 20 keV - 2 MeV energy range).

The time-integrated spectrum of the burst
(from T0 to T0+82.176 s) is well fitted
(in the 20 keV - 2 MeV range) by a power-law with
exponential cutoff (CPL) model:
dN/dE ~ E^{alpha}*exp(-(2+alpha)*E/Epeak), for which:
the photon index alpha = -1.1(-0.34,+0.4), and
the peak energy Ep = 134(-30,+56) keV (chi2 = 57/61 dof).

The spectrum at the maximum count rate,
measured from T0 to T0+8.448 s, is also well fitted
(in the 20 keV - 2 MeV range) by CPL model, for which:
the photon index alpha = -0.86(-0.20,+0.22), and
the peak energy Ep = 178(-23,+33) keV (chi2 = 49/61 dof).

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