GCN Circular 23859

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 190203A (Swift/BAT detection: Lien et al., GCN 23845
Not found
 
 
) 
triggered Konus-Wind at T0=56630.443 s UT (15:43:50.443).

The KW light curve shows a multi-peaked structure in the interval
from T0-39 s to T0-58 s.
The emission is seen up to ~4 MeV.

As observed by Konus-Wind, the burst had a fluence of
(4.9 �� 0.5)x10^-5 erg/cm2 and a 64-ms peak energy flux,
measured from T0+20.352, of (3.5 �� 0.4)x10^-6 erg/cm2
(both in the 20 keV - 10 MeV energy range).

The time-integrated spectrum (measured from T0 to T0+57.344 s)
is best fit in the 20 keV - 15 MeV range by a cutoff power-law
(CPL) function with the following model parameters:
the photon index alpha = -0.45(-0.11,+0.12),
and the peak energy Ep = 314(-22,+25) keV,
chi2 = 98/98 dof.
Fitting this spectrum with the GRB (Band) function yields
the same alpha and Ep, and only an upper limit on beta (<-2.7).

The spectrum near the peak count rate (measured from T0+16.640
to T0+24.574 s) is best fit in the 20 keV - 15 MeV range by
the CPL function with the following model parameters:
the photon index alpha = -0.17(-0.16,+0.18),
and the peak energy Ep = 348(-29,+34) keV,
chi2 = 90/98 dof.
Fitting this spectrum with the GRB (Band) function yields
the same alpha and Ep, and only an upper limit on beta (<-2.5).

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB190203_T56630/

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