Pseudo-redshifts of Gamma-Ray Bursts Derived from the L–T–E Correlation

Abstract The X-ray afterglow of many gamma-ray bursts (GRBs) exhibits a plateau phase before the normal power-law decay stage, which may be related to continued activities of the central engine. Tang et al. collected 174 such GRBs and confirmed the so-called L – T – E correlation which involves three key parameters, i.e., the isotropic γ -ray energy E γ ,iso of the prompt phase, the end time T a of the plateau phase, and the corresponding X-ray luminosity L X . In this study, the L – T – E correlation is confirmed and updated as L X ∝ T a − 0.99 E γ , iso 0.86 with a large sample consisting of 210 plateau GRBs with known redshifts. The tight correlation is then applied to derive the pseudo-redshift of other 130 plateau GRBs whose redshifts are not directly measured. Statistical analysis is also carried out on this pseudo-redshift sample.