| Description |
The deepest Herschel surveys have established a distinction between steady main sequence star formation, whose rate is closely tied to galaxy mass at a given redshift, and ^ated starburst activity in ordinary, L*(IR) galaxies at z > 1.5. They have also shown that supermassive black hole growth occurs mainly through secular processes in these main sequence galaxies, and have revealed otherwise obscured AGN missed by the deepest X-ray surveys. However, the physical processes that trigger starbursts, and the relation between star formation, AGN activity, and the structural properties of galaxies at this peak era of galaxy growth, are far from clear. We propose a survey to address these questions by measuring far-infrared luminosities and star formation rates for a large sample of high redshift galaxies with deep, high-resolution near-infrared imaging from the CANDELS HST WFC3 Treasury program. Herschel PACS and SPIRE observations deep enough to detect 700+ L*(IR) galaxies at z > 1.5 will be obtained for the five CANDELS fields and correlated with the detailed morphological and structural properties that only HST/WFC3 imaging can provide. We will establish whether interactions and mergers drive starburst activity, and examine their r^ance for fueling AGN activity. The improved statistics will allow a definitive measure of the space density of L*(IR) galaxies at z=2, a basic (and currently very uncertain) demographic quantity for the history of cosmic star formation. The survey will provide a legacy of targets for detailed investigation with ALMA, tripling (beyond GOODS-South alone) the number of ALMA-accessible fields with the deepest Herschel data. |
