GCN Circular 35713
Subject
Konus-Wind detection of GRB 240205A (short)
Date
2024-02-11T15:33:36Z (10 months ago)
From
Dmitry Frederiks at Ioffe Institute <fred@mail.ioffe.ru>
Via
legacy email
D. Frederiks, A.Lysenko, A. Ridnaia, D. Svinkin,
A. Tsvetkova, M. Ulanov, and T. Cline,
on behalf of the Konus-Wind team, report:
The short-duration GRB 240205A
(Fermi GBM Final Real-time Localization: GCN 35679;
Glowbug gamma-ray detection: Cheung et al., GCN 35707;
IPN triangulation: Svinkin et al., GCN 35710)
triggered Konus-Wind at T0=73586.689 s UT (20:26:26.689).
The burst light curve shows a single pulse,
which starts at ~T0-0.2 s and has a total duration of ~0.45 s.
The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB240205_T73586/
As observed by Konus-Wind, the burst
had a fluence of 5.45(-0.84,+0.89)x10^-7 erg/cm2,
and a 16-ms peak flux, measured from T0-0.016 s,
of 4.13(-0.92,+1.08)x10^-6 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).
Since the brightest part of the burst emission
was detected before the trigger, the spectral analysis
was performed using the KW 3-channel light curve data.
Modelling the KW 3-channel time-integrated spectrum
(measured from T0-0.192 s to T0+0.256 s)
by a power law with exponential cutoff (CPL) model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep),
yields alpha = -0.10(-0.38,+0.48) and Ep = 241(-46,+52) keV.
Modelling the KW 3-channel spectrum near the peak count rate
(measured from T0-0.064 s to T0) by the CPL model
yields alpha = -0.30(-0.48,+0.64) and Ep = 317(-82,+136) keV.
All the quoted errors are at the 68% confidence level.
All the quoted values are preliminary.