Abstract

The epoch between reionization and the peak of cosmic star formation (z~3-6) encompasses an important growth phase of the Universe as it transitions from being interstellar medium-dominated to stellar mass-dominated. Here, I present two projects, both with the goal of building techniques to efficiently and cleanly identify extreme, massive systems at z~3-6 in order to take a census of massive galaxies and overdense structures at this critical epoch. In my first project, I pilot the 2mm technique, using ALMA 2mm imaging of existing samples of bright dusty star-forming galaxies (DSFGs) selected at 850μm-1mm to quickly and easily isolate the “needle in a haystack” DSFGs that sit at z > 4 or beyond. In my second project, I aim to make a 3D rendering of the SSA22 protocluster structure with HET/VIRUS spectroscopic data to learn about the physical process of cluster assembly during this critical epoch and to anchor future protocluster science with HETDEX.