The X-ray Luminosity Function Evolution of Quasars and the Correlation Between the X-ray and Ultraviolet Luminosities

TL;DR

This study analyzes how quasar X-ray luminosity functions evolve over redshift and examines the intrinsic correlation between X-ray and ultraviolet luminosities using a large quasar sample, revealing less evolution in X-ray luminosity and establishing a specific power-law relation.

Contribution

It provides new insights into the evolution of quasar X-ray luminosity functions and quantifies the intrinsic X-ray/UV luminosity correlation with a large, verified sample.

Findings

Quasars show less evolution in X-ray luminosity than in other wavebands.

The intrinsic X-ray/UV luminosity correlation follows a power law with index 0.28.

Derived the X-ray luminosity function and density evolution for quasars.

Abstract

We explore the evolution of the X-ray luminosity function of quasars and the intrinsic correlation between the X-ray and 2500\AA $\,$ ultraviolet luminosities, utilizing techniques verified in previous works and a sample of over 4000 quasars detected with Chandra and XMM-Newton in the range $0<z<5$. We find that quasars have undergone significantly less evolution with redshift in their total X-ray luminosity than in other wavebands. We then determine that the best fit intrinsic power law correlation between the X-ray and ultraviolet luminosities, of the form $L'_{\rm X} \propto ({L'_{\rm UV}})^{\gamma}$, is $\gamma=0.28\pm$0.03, and we derive the luminosity function and density evolution in the X-ray band. We discuss the implications of these results for models of quasar systems.