Chris Fassnacht

Title: Dark and Luminous Matter at Moderate Redshifts

Abstract: Current simulations of galaxy formation make predictions
about how mass will be distributed in galaxy halos.  Using the
technique of gravitational lensing, it is becoming possible to measure
details of mass distributions in galaxies beyond the local Universe
and, thus, to compare observations directly to simulations for samples
of cosmologically distant objects.  I will describe results from two
ongoing projects that take advantage of high-resolution space- and
ground-based imaging, including Keck laser guide star adaptive optics
imaging.  The first combines strong and weak gravitational lensing to
quantify the relative contributions of the dark and luminous matter in
galaxies on scales from 10 kpc to nearly 1 Mpc.  The second focuses on
detecting the subhalos predicted by simulations, via both direct
imaging and gravitational lens modeling.