A. Shapley: Galaxy Formation in protoclusters at high redshift
Thousands of UV-selected galaxies at z>1.5 with spectroscopic confirmation from Keck. 25% contain AGN. From clustering length (4 Mpc) the DM halo mass is derived to roughly 10^11.5-12 solar masses and these objects are presumably the progenitors of nowadays ellipticals (by following halo-evolution in simulations).
The highest X-ray detected cluster is at z=1.45. The speaker and collaborators find protoclusters at z>2 also from UV and measure/find the overdenities (factor 7) in a redshift subslice. The galaxies there have double stellar mass than the ones outside the cluster. They find the morphologies not to fall on the Hubble sequence, but I wonder if they took into account that even normal galaxies look very different in different wavelenth, especially in rest-frame UV which the HST images were made in, if I got it right.