Skip to main content
Testing. You are viewing the public testing version of GCN. For the production version, go to
New Announcement Feature, Code of Conduct, Circular Revisions. See news and announcements

GCN Circular 31429

Konus-Wind detection of GRB 220107A
2022-01-10T19:41:10Z (2 years ago)
Anna Ridnaia at Ioffe Institute <>
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 220107A
(Fermi/GBM trigger #663259536: Fermi GBM Team, GCN 31399;
Kunzweiler et al., GCN 31400; Veres and Meegan, GCN 31406;
Swift/BAT-GUANO localization: DeLaunay et al., GCN 31402;
AstroSat CZTI detection: Suresh et al., GCN 31408)
triggered Konus-Wind at T0=53142.427 s UT (14:45:42.427).

The burst light curve shows a multipeaked structure
started at ~T0-7.6 s with a total duration of ~110.8 s.
The emission is seen up to ~2 MeV.

The Konus-Wind light curve of this GRB is available at

As observed by Konus-Wind, the burst
had a fluence of 5.48(-0.30,+0.34)x10^-5 erg/cm2,
and a 64-ms peak flux, measured from T0+81.344 s,
of 8.18(-1.55,+1.54)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+105.984 s)
is best fit in the 20 keV - 2 MeV range
by a power law with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
with  alpha = -1.02(-0.11,+0.12)
and Ep = 247(-24,+30) keV (chi2 = 53/61 dof).
Fitting by a GRB (Band) model yields the same alpha and Ep,
and an upper limit on the high energy photon index: beta < -2.4
(chi2 = 53/60 dof).

The spectrum near the maximum count rate
(measured from T0+73.984 to T0+89.600 s)
is best fit in the 20 keV - 2 MeV range
by the GRB (Band) model with the following parameters:
the low-energy photon index alpha = -0.86(-0.11,+0.12),
the high energy photon index beta = -2.91(-1.53,+0.32),
the peak energy Ep = 186(-15,+17) keV
(chi2 = 46/60 dof).

Assuming the redshift z=1.246 (Castro-Tirado et al., GCN 31423)
and a standard cosmology with H_0 = 67.3 km/s/Mpc, Omega_M = 0.315,
and Omega_Lambda = 0.685 (Planck Collaboration, 2014),
we estimate the isotropic energy release E_iso to (2.3 �� 0.1)x10^53 erg,
the isotropic luminosity L_iso to (7.8 �� 1.5)x10^52 erg/s,
the rest-frame peak energy of the time-integrated spectrum Epi,z to (555 ��
67) keV,
and the rest-frame peak energy of the 'peak' spectrum Epp,z to (418 �� 38)
With these values, GRB 220107A is within 68% prediction bands for
for both 'Amati' and 'Yonetoku' relations for the sample of >300 long KW
with known redshifts (Tsvetkova et al., 2021, ApJ, 908, 83),

All the quoted errors are at the 90% confidence level.
All the quoted values are preliminary.
Looking for U.S. government information and services? Visit