The space distribution of faint quasars from the CFHT survey

Abstract

Basic data are presented for 163 QSOs brighter than B = 20.5 selected from 1000 A/mm CFHT blue grens observations. The data are used to investigate the form of the evolution of QSOs in order to obtain their luminosity functions, and to predict their magnitude and density distributions to allow comparison with the results of other surveys. Less than 5 percent of the QSOs have z greater than 2.5 despite the ease of detecting them up to z = 3.4, so high-redshift QSOs are rare. The surface density of QSOs brighter than m = 20.5 is 30/sq deg. While the luminosity-dependent density evolution models of Schmidt and Green (1983) are found to fit the data well, a smooth cutoff to the evolution at high redshifts is proposed which implies a density maximum at z of roughly 1.7. The clustering properties of the sample QSOs are discussed and it is shown, in agreement with previous studies, that while clustering is not a general phenomenon among QSOs, significant density enhancements apparently do exist. 26 references.