Redshift Dependent Lag-Luminosity Relation in 565 BASTE Gamma Ray Bursts

TL;DR

This study reveals a new redshift-dependent lag-luminosity relation for gamma-ray bursts, improving understanding of their luminosity behavior across different redshifts and confirming its robustness with other indicators.

Contribution

The paper introduces a novel redshift-dependent lag-luminosity relation for GRBs, incorporating redshift into the lag-luminosity correlation, which enhances previous models.

Findings

Established a new lag-luminosity relation with high correlation coefficient (0.77).

Validated the relation using the Amati relation with an even higher correlation (0.92).

Indicates the lag-luminosity relation should depend on redshift in future observations.

Abstract

We compared redshifts $z_Y$ from Yonetoku relation and $z_{lag}$ from the lag-luminosity relation for 565 BASTE GRBs and were surprised to find that the correlation is very low. Assuming that the luminosity is a function of both $z_Y$ and the intrinsic spectral lag $\tau_{lag}$, we found a new redshift dependent lag-luminosity relation as $L=7.5\times 10^{50}{\rm erg/s}(1+z)^{2.53}\tau_{lag}^{-0.282}$ with the correlation coefficient of 0.77 and the chance probability of $7.9\times 10^{-75}$. To check the validity of this method, we examined the other luminosity indicator, Amati relation, using $z_Y$ and the observed fluence and found the correlation coefficient of 0.92 and the chance probability of $5.2\times 10^{-106}$. Although the spectral lag is computed from two channels of BATSE, our new lag-luminosity relation suggests that a possible lag-luminosity relation in the \swift era should also depend on redshift.