Astronomy Colloquium: Caitlin Casey

Date: Tue. February 13th, 2018, 2:30 pm-3:30 pm
Location: Sears 552

The Universe’s Most Extreme Star-Forming Galaxies in the Most Extreme Environments

Caitlin Casey (Texas)

Dusty star-forming galaxies host the most intense stellar nurseries in the Universe. Their unusual characteristics (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. Although rare today, these unusual galaxies were factors of 1000 times more prevalent 10 billion years ago, contributing significantly to the buildup of the Universe’s stars during catastrophic galaxy-galaxy collisions that ignited shortlived but extremely powerful bursts of star formation. Their presence in massive galaxy protoclusters — precursors of galaxy clusters, the most massive gravitationally bound objects in the Universe — only revealed quite recently, pose intriguing questions regarding the collapse of the cosmic web on immense physical scales. I will discuss the unique origins of such a rare galaxy population, and what they teach us about galaxy growth and the collapse of large scale structure in an evolving Universe.