We have designed the Extremely Luminous Quasar Survey ( ELQS ) to provide a highly complete census of unobscured UV-bright quasars during the cosmic noon , z = 2.8 - 5.0 .
Here we report the discovery of 70 new quasars in the ELQS South Galactic Cap ( ELQS-S ) quasar sample , doubling the number of known extremely luminous quasars in 4 , 237.3 deg ^ { 2 } of the SDSS footprint .
These observations conclude the ELQS and we present the properties of the full ELQS quasar catalog , containing 407 quasars over 11 , 838.5 deg ^ { 2 } .
Our novel ELQS quasar selection strategy resulted in unprecedented completeness at the bright end and allowed us to discover 109 new quasars in total .
This marks an increase of \sim 36 \% ( 109/298 ) to the known population at these redshifts and magnitudes , while we further are able to retain a selection efficiency of \sim 80 \% .
On the basis of 166 quasars from the full ELQS quasar catalog , who adhere to the uniform criteria of the 2MASS point source catalog , we measure the bright-end quasar luminosity function ( QLF ) and extend it one magnitude brighter than previous studies .
Assuming a single power law with exponential density evolution for the functional form of the QLF , we retrieve the best fit parameters from a maximum likelihood analysis .
We find a steep bright-end slope of \beta \approx - 4.1 and we can constrain the bright-end slope to \beta \leq - 3.4 with 99 \% confidence .
The density is well modeled by the exponential redshift evolution , resulting in a moderate decrease with redshift ( \gamma \approx - 0.4 ) .