GCN Circular 31526
Subject
Konus-Wind detection of GRB 220124A
Event
Date
2022-01-25T15:13:25Z (4 years ago)
From
Dmitry Frederiks at Ioffe Institute <fred@mail.ioffe.ru>
D. Frederiks, A.Lysenko, A. Ridnaia, D. Svinkin,
A. Tsvetkova, M. Ulanov, and T. Cline,
on behalf of the Konus-Wind team, report:
The long GRB 220124A (AstroSat-CZTI detection: Prasad et al., GCN Circ. 31521;
GECAM detection: Liu et al., GCN 31524;
IPN localization: Kozyrev et al., GCN 31525)
triggered Konus-Wind (KW) at T0=13059.043 s UT (03:37:39.043).
The burst light curve shows a series of bright, multi-peaked pulses,
which starts at ~T0-10 s and has a total duration of ~250 s.
The emission is seen up to ~10 MeV.
The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB220124_T13059/
As observed by Konus-Wind, the burst had
a fluence of (2.0 �� 0.2)x10^-4 erg/cm^2 and
a 64-ms peak energy flux, measured from T0 + 40.512 s,
of (6.0 �� 0.9)x10^-6 erg/cm^2/s (both in the 20 keV - 10 MeV energy range).
The time-integrated spectrum (measured from T0 to T0+242.432 s)
is best fit in the 20 keV - 15 MeV range
by the GRB (Band) function with the following model parameters:
the low-energy photon index alpha = -0.81 (-0.06,+0.07),
the high energy photon index beta = -2.64 (-0.36,+0.22),
the peak energy Ep = 262 (-18,+18) keV,
chi2 = 86/97 dof.
The spectrum near the peak count rate (measured from T0+39.168 s
to T0+44.544 s) is best fit in the 20 keV - 15 MeV range
by the GRB (Band) function with the following model parameters:
the low-energy photon index alpha = -0.75 (-0.09,+0.10),
the high energy photon index beta = -2.61 (-0.89,+0.31),
the peak energy Ep = 381 (-45,+53) keV,
chi2 = 109/91 dof.
All the quoted errors are estimated at the 90% confidence level.
All the presented results are preliminary.