GCN Circular 34414

D. Frederiks, A.Lysenko, A. Ridnaia, D. Svinkin,
A. Tsvetkova,  M. Ulanov, and T. Cline,
on behalf of the Konus-Wind team, report:

Assuming the spectrum and the observer-frame energetics of the very bright
GRB 230812B measured by KW (GCN 34403
Not found
 
 
); the source redshift z=0.360
(de Ugarte Postigo et al., GCNs 34409
Not found
 
 
, 34410
Not found
 
 
); 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 burst isotropic energy release E_iso to (1.09 ± 0.02)x10^53 erg,
the isotropic peak luminosity L_iso to (1.25 ± 0.05)x10^53 erg/s,
the rest-frame peak energy of the time-integrated spectrum Ep,i,z to (392 ± 16) keV,
and the rest-frame peak energy at the peak of the emission Ep,p,z to (604 ± 41) keV.

With the obtained estimates, GRB 220627A fits perfectly both 'Amati' and 'Yonetoku'
relations derived for the sample of >300 long KW GRBs with known redshifts
(Tsvetkova et al., 2017; Tsvetkova et al., 2021), see
http://www.ioffe.ru/LEA/GRBs/GRB230812_T68292/GRB230812B_rest_frame.pdf
This suggests that an energy reservoir powering the burst and its emission mechanism
are similar to that typical of long-duration GRBs.

All the quoted errors are estimated at the 90% confidence level.
All the presented results are preliminary.