D. Frederiks, A. Ridnaia, D. Svinkin, A. Lysenko,
M. Ulanov (all - Ioffe Institute), and A. Tsvetkova
(Ioffe Institute/University of Cagliari), report:
Konus-Wind (KW) detected a short X-ray burst on 2022-10-14
in time interval from 19:21:39.205 UTC to 19:21:42.149 UTC.
Corrected for the propagation from low-Earth orbit to Wind (~1.05 s),
the burst arrival time is consistent with the detection time
of a bright short X-ray burst from SGR 1935+2154, reported
by GECAM and HEBS (Atel #15682), which, in turn, is consistent
with the dedispersed topocentric time of a bright radio burst
detected from SGR 1935+2154 by CHIME (Atel #15681).
The event was detected by KW in the waiting mode and no detailed
information on its temporal structure is available.
The emission is seen in two instrument's energy bands:
G1(20-80 keV) and G2 (80-320 keV), while no statistically
significant signal is visible above 320 keV.
A time-averaged spectrum of the burst can be described
in the 20-1300 keV range by a power law with exponential
cutoff model: dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
with the peak energy Ep of (40 �� 6) keV, which is slightly
higher than a typical Ep of multiple bright SGR 1935+2154
bursts detected by KW recently (GCN Circ. 32768).
We also note that the October 14 burst Ep is about twice
as lower as the peak energy (~85 keV) measured by KW for
the much radio-brighter event SGR/FRB200428 from the same
magnetar (Ridnaia et al. 2021, NatAstr. 5, 372).
From the KW detection, we estimate the total 20-500 keV fluence
of the burst to (5.7 �� 0.6)x10^-7 erg/cm2, about two times
lower than that of SGR/FRB200428.
This GCN circular duplicates ATel #15686.