[vsnet-grb-info 21683] Konus-Wind of observation of GRB 190117A

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  23782
SUBJECT: Konus-Wind of observation of GRB 190117A
DATE:    19/01/24 14:12:03 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 190117A (Agile/MCAL detection: Ursi et al., GCN 23752;
Insight-HXMT/HE detection: Xiao et al., GCN 23759,
IPN triangulation: Hurley et al., GCN 23764)
triggered Konus-Wind (KW) at T0=52611.684 s UT (14:36:51.684).

The burst light curve shows a weak emission pulse at ~T0-10 s and
three bright pulses in the interval from ~T0 to ~T0+30 s.
A total duration of the burst (T100) is ~36.3 s.
The emission is seen up to ~15 MeV.

As observed by Konus-Wind, the burst had a fluence of
(4.1 ± 0.3)x10^-5 erg/cm2 and a 64-ms peak energy flux,
measured from T0+1.984, of (1.66 ± 0.13)x10^-5 erg/cm2
(both in the 20 keV - 10 MeV energy range).

The time-integrated spectrum (measured from T0 to T0+33.024 s)
is best fit in the 20 keV - 15 MeV range
by the GRB (Band) function with the following model parameters:
the low-energy photon index alpha = -1.19 (-0.08,+0.07),
the high energy photon index beta = -2.67 (-0.60,+0.27),
the peak energy Ep = 190 (-17,+18) keV
(chi2 = 90/97 dof).

The spectrum near the peak count rate (measured from T0
to T0+8.448 s) is best fit in the 20 keV - 15 MeV range
by the GRB (Band) function with the following model parameters:
alpha = -1.04 (-0.08,+0.07),
beta = -2.68 (-0.44,+0.23),
Ep = 208 (-18,+20) keV
(chi2 = 74/97 dof).

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB190117_T52611/

All the quoted errors are estimated at the 68% confidence level.
All the presented results are preliminary.