GCN Circular 31555
Subject
Konus-Wind detection of GRB 220130A
Event
Date
2022-02-06T12:47:42Z (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 220130A (GECAM detection: Zhao et al., GCN Circ. 31533;
Fermi-GBM detection: Lesage et al., GCN Circ. 31538;
IPN localization: Svinkin et al., GCN 31548)
triggered Konus-Wind (KW) at T0=83760.565 s UT (23:16:00.565).
The burst light curve shows a weak emission episode in the interval
from ~T0-90 s to ~T0-50 s, followed by a bright, multi-peaked pulse,
which starts at ~T0-40 s and has a total duration of ~130 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/GRB220130_T83760/
As observed by Konus-Wind, the burst had
a fluence of (7.6 �� 1.2)x10^-5 erg/cm^2 and
a 64-ms peak energy flux, measured from T0 + 13.824 s,
of (4.9 �� 1.2)x10^-6 erg/cm^2/s (both in the 20 keV - 10 MeV energy range).
The time-integrated spectrum (measured from T0 to T0+98.560 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 = -0.74 (-0.13,+0.15),
the high energy photon index beta = -2.50 (-0.53,+0.25),
the peak energy Ep = 236 (-25,+28) keV,
chi2 = 89/97 dof.
The spectrum near the peak count rate (measured from T0+8.448 s
to T0+16.640 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 = -0.78 (-0.14,+0.22),
the high energy photon index beta = -2.59 (-0.70,+0.34),
the peak energy Ep = 397 (-95,+86) keV,
chi2 = 110/97 dof.
All the quoted errors are estimated at the 90% confidence level.
All the presented results are preliminary.