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 ${L}_{{\rm{X}}}\propto {T}_{{\rm{a}}}^{-0.99}{E}_{\gamma ,\mathrm{iso}}^{0.86}$ 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.

Keywords

• Gamma-ray bursts
• Magnetars
• Neutron stars
• Markov chain Monte Carlo