Uncovering Massive Galaxy Protoclusters in the Early Universe with the South Pole Telescope

The sub-millimeter galaxy (SMG) population represent the most intense stellar nurseries in the Universe. Their high star formation rates of 200-2000 Msun/yr (compared to the Milky Way’s 1 Msun/yr) pose a unique challenge for cosmological simulations of how galaxies form and evolve, particularly in the first few billion years after the Big Bang. They are 1000 times more prevalent 10 billion years ago than today, highlighting a peak epoch of galaxy building, and contributing significantly to the buildup of the Universe’s stars.

SMGs are ubiquitous in distant, massive galaxy “protoclusters”, the precursors of rich galaxy clusters -- the most massive gravitationally bound objects in the Universe. As such they can elucidate the formation modes of cluster cores, the assembly of the “Brightest Cluster Galaxies”, and the collapse of the cosmic web over large scales. I will a present an ongoing survey with the South Pole Telescope to search for protoclusters of galaxies in the early (z>3) Universe, and discuss what they teach us about galaxy growth and the collapse of large scale structure in an evolving Universe.

Speaker: Scott Chapman (Dalhousie University)