Are quasars really at the large distances indicated by their redshifts?
The short answer is Yes! Stockton (1978, ApJ, 223, 747) observed faint galaxies near in the sky to bright quasars at moderate redshifts. He chose quasars with moderate redshifts so he would still be able to see galaxies at the redshift of the quasar. He found that a good fraction of the redshifts of the faint galaxies agreed with the redshifts of the quasars. In other words, quasars are associated with galaxies that have the same redshift as the quasar and have just the brightness expected if the quasars are at their cosmological distances. Thus at least some quasars are at the distance indicated by their redshifts, and this includes some of the most luminous quasars: for example 3C273. Thus the simple answer selected by Occam’s razor is that all quasars are at the distances indicated by their redshifts. A further argument in favor of cosmological redshifts for quasars is the essentially perfect rank ordering implied by the fact that quasar absorption line system always have redshifts