  We use the first data release of the 2-degree Field Quasar survey to
investigate the effect of gravitational magnification by foreground absorbing
systems on background quasars. We select two populations of quasars from this
sample: one with strong MgII/FeII absorbers and one without. The selection is
done in such a way that the two populations have the same redshift distribution
and the absorber detection procedure discards possible biases with quasar
magnitude. We then compare their magnitude distributions and find a relative
excess of bright quasars with absorbers. This effect is detected at the 2.4,
3.7 and 4.4 sigma levels in u-, b- and r-bands. Various explanations of the
observed phenomenon are considered and several lines of evidence point towards
gravitational lensing causing some of the differences observed in the magnitude
distributions. We note that physical quasar-absorber associations may
contribute to some extent to the observed correlations for low quasar-absorber
velocity differences. We discuss the implications of these findings and propose
future work which will allow us to strengthen and extend the results presented
here.
