Fig. 22
The redshift distribution of quasars from this catalog is displayed in black. The same distribution is shown for newly discovered quasars only (dashed blue histogram). Most of the SDSS-DR9 quasars have a redshift greater than 2. The redshift distribution of quasars from the SDSS-DR7 catalog (Schneider et al. 2010) is shown for comparison in red. The latter is dominated by quasars at low redshift. The present catalog contains 2.6 times more quasars at z > 2.15 than the DR7 catalog.
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.