2006ApJ...648..140B

The redshift distribution of all 46,400 quasars in the Sloan Digital Sky Survey (SDSS) Quasar Catalog, Third Data Release (DR3), is examined. Six peaks that fall within the redshift window below z=4 are visible. Their positions agree with the preferred redshift values predicted by the decreasing intrinsic redshift (DIR) model. A power spectrum analysis of the full data set confirms the presence of a single significant power peak at the expected redshift period. Power peaks with the predicted period are also obtained when the upper and lower halves of the redshift distribution are examined separately. The periodicity detected is in linear z, as opposed to log(1+z). Because the peaks in the SDSS quasar redshift distribution agree well with the preferred redshifts predicted by the intrinsic redshift relation, we conclude that this relation, and the peaks in the redshift distribution, likely both have the same origin, which may be intrinsic redshifts or a common selection effect. However, because of the way in which the intrinsic redshift relation was determined, it seems unlikely that one selection effect could have been responsible for both.