TITLE:   GCN CIRCULAR
NUMBER:  32126
SUBJECT: Konus-Wind detection of a burst from SGR 1935+2154 on 2022 May 25
DATE:    22/05/26 16:32:21 GMT
FROM:    Anna Ridnaia at Ioffe Institute  <ridnaia@mail.ioffe.ru>

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

A short, soft, SGR-like burst
triggered Konus-Wind on 2022 May 25 at
T0=25816.58 s UT (07:10:16.580).

The Konus-Wind ecliptic latitude response is consistent
with the SGR 1935+2154 position. So, taking in account
the ongoing bursting activity of this source, burst
time history, and softness of its spectrum (as observed
by Konus-Wind), we suggest that this burst is likely
a SGR flare originated from SGR 1935+2154.

The burst light curve shows a single pulse
started at ~T0-72 ms with a total duration of ~194 ms.
The emission is seen up to ~200 keV.

The Konus-Wind light curve of this burst is available at
http://www.ioffe.ru/LEA/SGRs/220525_T25816/

As observed by Konus-Wind, the burst
had a fluence of 2.55(-0.10,+0.10)x10^-6 erg/cm2,
and a 16-ms peak flux, measured from T0-0.014 s,
of 2.08(-0.16,+0.16)x10^-5 erg/cm2/s
(both in the 20 - 500 keV energy range).

The spectrum of the burst
(measured from T0 to T0+0.192 s)
is best fit in the 20 - 200 keV range
by a power law with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
with  alpha = 0.22(-0.54,+0.61)
and Ep = 36(-3,+2) keV (chi2 = 20/18 dof).

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