A thorough study of QSO-galaxy correlations has been done on a region close
to the North Galactic Pole using a complete subsample of the optically selected
CFHT/MMT QSO survey and the galaxy catalog of Odewahn and Aldering (1995).
Although a positive correlation between bright QSOs and galaxies is expected
because of the magnification bias effect, none is detected. On the contrary,
there is a significant (>99.6%) anticorrelation between z<1.6 QSOs and red
galaxies on rather large angular distances. This anticorrelation is much less
pronounced for high redshift z>1.6 QSOs, which seems to exclude dust as a cause
of the QSO underdensity. This result suggests that the selection process
employed in the CFHT/MMT QSO survey is losing up to 50% of low redshift z<1.6
QSOs in regions of high galaxy density. The incompleteness in the whole z<1.6
QSO sample may reach 10% and have important consequences in the estimation of
QSO evolution and the QSO autocorrelation function.Comment: 17 pages LaTeX (aasms4), plus 6 EPS figures. To be published in the
Astronomical Journa