[vsnet-grb-info 22728] Konus-Wind observation of GRB 190611B

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  24827
SUBJECT: Konus-Wind observation of GRB 190611B
DATE:    19/06/14 12:22:39 GMT
FROM:    Dmitry Frederiks at Ioffe Institute  <fred at mail.ioffe.ru>

D. Frederiks, S. Golenetskii, R.Aptekar, A. Kozlova,
A.Lysenko,  D. Svinkin, A. Tsvetkova,  M. Ulanov, and T. Cline,
on behalf of the Konus-Wind team, report:

The long GRB 190611B
(Fermi GBM detection: Malacaria & Meegan, GCN 24794;
IPN triangulation: Hurley et al., GCN 24811)
triggered Konus-Wind (KW) at T0=82065.599 s UT (22:47:45.599).

The light curve of the burst shows two broad, multi-peaked pulses.
The total duration of the burst is ~130 s.
The emission is seen up to ~10 MeV.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB190611_T82065/

As observed by Konus-Wind, the burst had
a fluence of (9.2 ± 1.0)x10^-5 erg/cm2 and
a 64-ms peak energy flux, measured from T0+17.344,
of (1.33 ± 0.11)x10^-5 erg/cm2 (both in the 20 keV - 10 MeV
energy range).

The time-integrated spectrum (measured from T0 to T0+117.760 s)
is best fit in the 20 keV - 20 MeV range
by the GRB (Band) function with the following model parameters:
the low-energy photon index alpha = -1.01 (-0.08,+0.08),
the high energy photon index beta = -2.74 (-0.88,+0.29),
the peak energy Ep = 250 (-21,+24) keV,
chi2 = 68/97 dof.

The spectrum near the peak count rate (measured from T0+67.840 s
to T0+77.568 s) is best fit in the 20 keV - 20 MeV range
by the GRB (Band) function with the following model parameters:
the low-energy photon index alpha = -0.78 (-0.08,+0.09),
the high energy photon index beta = -2.20 (-0.13,+0.10),
the peak energy Ep = 307 (-29,+33) keV,
chi2 = 83/97 dof.

All the quoted errors are estimated at the 90% confidence level.
All the presented results are preliminary.