[vsnet-grb-info 25937] Konus-Wind detection of short/hard GRB 200623B

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  28037
SUBJECT: Konus-Wind detection of short/hard GRB 200623B
DATE:    20/06/28 18:08:03 GMT
FROM:    Anastasia Tsvetkova at Ioffe Institute  <tsvetkova at mail.ioffe.ru>

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

The short-duration, hard-spectrum GRB200623B
(IPN triangulation: Ridnaia et al., GCN 28024)
triggered Konus-Wind at T0=64972.561 s UT (18:02:52.561).

The light curve of the burst shows two pulses
in the interval from ~T0-0.2 s to ~T0+0.3  s.
The emission is seen up to ~1 MeV.

As observed by Konus-Wind, the burst
had a fluence of 1.02(-0.23,+0.57)x10^-6 erg/cm2,
and a 64-ms peak energy flux, measured from T0-0.086 s,
of 6.65(-1.47,+3.74)x10^-6 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

Fitting the time-integrated 3-channel spectrum of the burst
(measured from T0-0.118 s to T0+0.304 s)
in the 20 keV - 1.5 MeV range
by a power law with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
yields alpha = -0.37(-0.41,+0.59),
and Ep = 753(-217,+582) keV.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB200623_T64972/

All the quoted errors are at the 68% confidence level.
All the quoted values are preliminary.