TITLE:   GCN CIRCULAR
NUMBER:  31365
SUBJECT: GRB 220101A : Eiso equals the maximum isotropic GRB energy
DATE:    22/01/02 09:38:15 GMT
FROM:    Jean-Luc Atteia at IRAP  <jean-luc.atteia@irap.omp.eu>

J.-L. Atteia reports:

A quick calculation of the isotropic energy of GRB 220101A, whose prompt emission was detected from space by Swift/BAT (A. Tohuvavohu et al. 2022, GCN 31347), Fermi/LAT (M. Arimoto et al. 2022, GCN 31350), AGILE (A. Ursi et al. 2022, GCN 31354), and Fermi/GBM (Lesage et al. 2022, GCN 31360) was done using the redshift z = 4.618 measured at Xinlong (Fu et al. 2022, GCN 31353) and NOT (Fynbo te al. 2022, GCN 31359) and the spectral parameters measured by Fermi/GBM (Lesage et al. 2022, GCN 31360).

The isotropic energy of GRB 220101A reaches 3.7 10^54 ergs, equaling the maximum isotropic energy measured for GRBs to date (Atteia et al. 2017, ApJ 837, 119).