Abstract:

During the last decade, gravitational lensing has become a great tool to
constrain the mass of various structures: exoplanets, stars, galaxies,
clusters, large-scale structures, etc.
I will show that lensing can also be used to probe the mass distribution
of absorber systems seen in quasar spectra. I will present a method to
measure the signal due to the magnification effects of absorbing galaxies
and apply it to a large sample of SDSS quasar spectra.