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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.
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