Quasars associated with galaxies

The results of a statistical comparison of quasars in quasar-galaxy associations and quasars with absorption spectra are presented. Quasars in associations with small redshifts Z are found to be overluminous, which is, according to earlier studies, typical of absorption-line quasars. With increasing Z, association quasars lose this feature, and their mean luminosity falls below that of quasars without associated galaxies and without absorption. We also find extra quasar luminosity excess in quasar-galaxy associations with small angular separations (less than or equal to 120 arcsec). The redshift distribution of association quasars is to a large extent determined by that of visible galaxies and is substantially different from the distribution of absorption-line quasars.