TITLE: GCN CIRCULAR NUMBER: 32792 SUBJECT: Konus-Wind detection of a burst from SGR 1935+2154 on 2022 October 17 DATE: 22/10/18 14:35:09 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 October 17 at T0=40483.010 s UT (11:14:43.010).
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 ~T0-56 ms with a total duration of ~202 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/221017_T40483/
As observed by Konus-Wind, the burst had a fluence of 2.16(-0.10,+0.10)x10^-6 erg/cm2, and a 16-ms peak flux, measured from T0-0.006 s, of 2.84(-0.22,+0.22)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 - 500 keV range by a power law with exponential cutoff model: dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep) with alpha = -0.71(-0.50,+0.57) and Ep = 33(-7,+5) keV (chi2 = 15/19 dof).
All the quoted errors are at the 90% confidence level. All the quoted values are preliminary.