GCN Circular 38631
Subject
Konus-Wind detection of GRB 241204A (short/hard)
Date
2024-12-19T08:22:13Z (21 days ago)
From
Dmitry Svinkin at Ioffe Institute <svinkin@mail.ioffe.ru>
Via
Web form
V. Panteleeva, 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 241204A
(Fermi-LAT detection: Bissaldi et al., GCN 38436;
Fermi-GBM detection: Godwin et al., GCN 38441)
triggered Konus-Wind at T0=13159.909 s UT (03:39:19.909).
The burst light curve shows a single pulse
which starts at ~T0 and has a total duration of ~0.1 s.
The emission is seen up to ~7 MeV.
The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB241204_T13159/
As observed by Konus-Wind, the burst
had a fluence of 6.20(-1.01,+1.11)x10^-6 erg/cm2,
and a 16-ms peak flux, measured from T0+0.004 s,
of 1.45(-0.34,+0.37)x10^-4 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).
The time-averaged spectrum of the burst
(measured from T0 to T0+0.064 s)
is best fit in the 20 keV - 10 MeV range
by a power law with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
with alpha = -1.22(-0.11,+0.12)
and Ep = 3550(-1308,+4267) keV (pgstat = 62/73 dof).
Fitting by a GRB (Band) model yields the same alpha and Ep,
and an upper limit on the high energy photon index: beta < -1.62
(pgstat = 62/72 dof).
All the quoted errors are at the 90% confidence level.
All the quoted values are preliminary.