GCN Circular 32768
Subject
Konus-Wind observation of the recent SGR 1935+2154 activity
Date
2022-10-16T06:19:56Z (2 years ago)
From
Anna Ridnaia at Ioffe Institute <ridnaia@mail.ioffe.ru>
Since the last KW GCN on the ongoing SGR 1935+2154 activity
(Ridnaia et al., GCN 32204) the instrument triggered on
six bright bursts from the source.
The following is a list of the Konus-Wind triggers with preliminary
estimates of the burst fluences and peak fluxes.
------------------------------------------------------------------
# Date T0(KW) s UT Fl* PF**
------------------------------------------------------------------
1 20221012 56552.646 s UT(15:42:32.646) 3.09 +/-0.10 15.2 +/-1.3
2 20221013 7366.180 s UT(02:02:46.180) 3.30 +/-0.11 16.9 +/-1.4
3 20221013 81690.645 s UT(22:41:30.645) 5.75 +/-0.22 19.6 +/-1.5
4 20221014 25949.934 s UT(07:12:29.934) 1.92 +/-0.08 16.0 +/-1.5
5 20221014 50052.142 s UT(13:54:12.142) 0.71 +/-0.06 14.7 +/-1.8
6 20221014 61721.260 s UT(17:08:41.260) 1.88 +/-0.18 20.3 +/-2.4
------------------------------------------------------------------
* - Fluence (20-500 keV) in units of 1e-6 erg/cm2
** - Peak Flux (20-500 keV) on 16-ms time scale
in units of 1e-6 erg/cm2/s
The time-averaged spectra of the bursts are well 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 the following parameters:
------------------------------------------------------------------
# T100 Tbeg-Tend alpha Ep(keV) chi2/dof
------------------------------------------------------------------
1 0.434 0 - 0.256 0.54(-0.61,+0.68) 29(-3,+2) 12/19
2 0.330 0 - 0.256 -0.20(-0.38,+0.41) 33(-3,+2) 24/20
3 0.424 0 - 8.448 -0.05(-0.38,+0.41) 39(-2,+2) 48/40
4 0.202 0 - 0.192 -1.00(-0.48,+0.54) 27(-8,+5) 20/20
5 0.168 0 - 0.128 -0.5 fixed 25(-3,+4) 13/16
6 0.516 0 - 8.448 -1.36(-0.62,+1.29) 17(-10,+11) 48/40
------------------------------------------------------------------
The emission in all bursts is seen up to ~200 keV.
The Konus-Wind light curves of the bursts are available at
http://www.ioffe.ru/LEA/SGRs/221012_T56552/
http://www.ioffe.ru/LEA/SGRs/221013_T07366/
http://www.ioffe.ru/LEA/SGRs/221013_T81690/
http://www.ioffe.ru/LEA/SGRs/221014_T25949/
http://www.ioffe.ru/LEA/SGRs/221014_T50052/
http://www.ioffe.ru/LEA/SGRs/221014_T61721/
All the quoted errors are at the 90% confidence level.
All the quoted values are preliminary.