Abstract

Dusty star-forming galaxies (DSFGs) host the most intense stellar nurseries in the Universe. Their unusual characteristics (SFRs=200-2000Msun/yr) pose a unique challenge for cosmological simulations and galaxy formation theory, particularly at early times. Although rare today, they were factors of 1000 times more prevalent at z~2-5, contributing significantly to the buildup of the Universe’s stellar mass and the formation of high-mass galaxies. However, an ongoing debate lingers as to their evolutionary origins at high-redshift, whether or not they are triggered by major mergers of gas-rich disk galaxies, or if they are solitary galaxies continually fed pristine gas from the intergalactic medium. I will discuss some of the latest observational programs dedicated to understanding their origins at early times, including: 1. the contribution of dust-obscured galaxies to all of cosmic star-formation, 2. tools we can use to surmise the physical mechanisms driving such intense star-forming galaxies, and 3. what these extreme galaxies can teach us about the formation of massive galaxy clusters.