GCN Circular 38323
Subject
Konus-Wind detection of GRB 241115D / EP 241115a
Date
2024-11-26T15:15:20Z (8 days ago)
From
Dmitry Svinkin at Ioffe Institute <svinkin@mail.ioffe.ru>
Via
Web form
D. Svinkin, D. Frederiks, A. Lysenko, A. Ridnaia,
A. Tsvetkova, M. Ulanov, and T. Cline,
on behalf of the Konus-Wind team, report:
The long-duration GRB 241115D / EP 241115a
(EP-WXT detection: Hu et al., GCN 38239;
SVOM-GRM detection: Wang et al., GCN 38250)
was detected by Konus-Wind (KW) in the waiting mode
at T0(GRM) ~20736 s UT (05:45:36).
A Bayesian block analysis of the KW waiting mode data
in the 20-300 keV band reveals a >30 sigma count rate
increase in the interval from T0(GRM)-68 s to ~T0(GRM)+35 s.
The total burst duration is ~103 s.
The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB241115D/
The total burst fluence is 1.54(-0.21,+0.24)x10^-5 erg/cm^2,
and the 2.944 s peak energy flux, measured from T0-0.138 s,
is 7.10(-1.8,+1.4)x10^-7 erg/cm^2.
(both in the 20 keV - 10 MeV energy range).
The time-integrated spectrum of the burst,
measured from T0-68 s to T0+35 s,
can be described by a power law with exponential cutoff (CPL) model
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
with alpha = -1.74(-0.19,+0.53) and Ep = 102(-38,+24) keV.
The spectrum near the peak count rate,
measured from T0-3.082 s to T0+2.806 s,
can be described by a CPL model with
alpha ~-1.3 and Ep = 121(-22,+29) keV.
All the quoted errors are estimated at the 68% confidence level.
All the presented results are preliminary.