A study of six low redshift QSO pairs

TL;DR

This study investigates the dynamical properties of six low-redshift quasar pairs, revealing that their total mass exceeds that of their host galaxies, implying the presence of massive dark matter halos or group environments.

Contribution

It provides the first detailed dynamical analysis of low-redshift quasar pairs, highlighting their association with massive dark halos or galaxy groups.

Findings

Quasar pairs have excess dynamical mass compared to host galaxies.

Evidence suggests they reside in massive dark matter halos.

Some pairs may be part of galaxy groups or clusters.

Abstract

The dynamical properties of six SDSS quasar pairs at z < 0.8 are investigated. The pairs have proper transverse separation < 500 kpc, and velocity difference along the line of sight < 500 km/s. If they are bound systems their dynamical mass can be evaluated and compared with that of host galaxies. Evidence is found of an excess of the former mass with respect to the latter. This suggests that these quasar pairs are hosted by galaxies with massive dark halos or that they reside in a group/cluster of galaxies.