Title: Evolving Galaxies across Cosmic Time: The Individual and Ensemble Perspective
Abstract:
We have gained many new insights in the formation of the first galaxies at very high redshifts (z~8-10) and the major buildup of the most massive ellipticals, bulges and disks at the peak of cosmic star formation rate (z~2) in the last century. I will show how we need to study individual galaxies as well as the whole population to understand how galaxies form and evolve with time. I start with a simple model that links the galaxy properties to the underlying dark matter population and successfully predicts the UV luminosity function from z~10 to z=0. To constrain the mass assembly and early evolution of z~2 star-forming galaxies, I present a synergy between Hubble Space Telescope and Very Large Telescope data to resolve the stellar mass and star formation distribution on 1-2 kpc scales. We find that the massive z~2 galaxies already have mature bulges and reduced star formation activity in their center, sustaining their high star-formation rates of about hundred solar masses per year in their outskirts.