GCN Circular 35539
Subject
Konus-Wind detection of GRB 240112C
Date
2024-01-15T15:31:10Z (4 months ago)
From
Anna Ridnaia at Ioffe Institute <ridnaia@mail.ioffe.ru>
Via
Web form
A. Ridnaia, D. Frederiks, A. Lysenko, D. Svinkin,
A. Tsvetkova, M. Ulanov, and T. Cline,
on behalf of the Konus-Wind team, report:
The long-duration GRB 240112C
(Swift-BAT detection: Eyles-Ferris et al., GCN 35522;
Fermi-GBM detection: Veres at al., GCN 35533;
GRBAlpha detection: Dafcikova et al., GCN 34436)
triggered Konus-Wind at T0=63441.633 s UT (17:37:21.633).
The burst light curve shows a double-peaked structure,
which starts at ~T0-0.5 s and has a total duration of ~4 s.
The emission is seen up to ~2 MeV.
The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB240112_T63441/
As observed by Konus-Wind, the burst
had a fluence of 3.70(-0.39,+0.46)x10^-6 erg/cm2,
and a 64-ms peak flux, measured from T0+2.384 s,
of 3.30(-0.84,+0.88)x10^-6 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).
The time-averaged spectrum of the burst
(measured from T0 to T0+8.448 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 = -1.59(-0.22,+0.26)
and Ep = 79(-18,+18) keV (chi2 = 66/74 dof).
Fitting by a GRB (Band) model yields the same alpha and Ep,
and an upper limit on the high energy photon index: beta < -2.3
(chi2 = 64/73 dof).
All the quoted errors are at the 90% confidence level.
All the quoted values are preliminary.