Sackler Astronomy Colloquium

Title: 

Galaxy Evolution at the Peak Epoch of Cosmic Star Formation: Witnessing In-situ the Growth and Transformations of Young Galaxies

Abstract: 

Eight to eleven billion years ago, galaxies were undergoing their most rapid mass assembly phase, forming stars at prodigious rates 10 to 20 times faster than observed today in the Milky Way and other nearby galaxies.  While the statistical census of surveys measuring the global properties of faint distant galaxy populations and the fossil record from stars in present-day galaxies have enabled us to pin down when galaxies formed, detailed and resolved in-situ observations of individual young galaxies are required to understand how. 

The advent of sensitive state-of-the-art instrumentation at large ground-based telescopes and in space have allowed us to spatially- and spectrally-resolve galaxies out to the peak epochs of cosmic star and galaxy formation.  I will describe key results from observations mapping in detail the internal structure and motions, the distribution of stars and gas, and the physical conditions of gas in young galaxies.  I will discuss the implications for our understanding of the physical processes that drive the lifecycle of galaxies at early times -- from mass assembly, conversion of gas into stars, structural transformations, and feedback from massive stars and accretion onto growing supermassive black holes in the form of powerful galactic winds.  I will also highlight the exciting prospects in the next decade from the next generation of instruments and telescopes.