Faculty Candidate Lecture: Sarah Wellons

February 21, 2019 - 2:30pm to 3:30pm

Title:Simulating the evolution of massive galaxies throughout cosmic history


Abstract: Observational work over the last decade has probed deeper and deeper into the Universe's history, revealing galaxies which formed in the first few billion years after the Big Bang.  Evidence is mounting that massive galaxies in the early Universe appear and behave very differently from those nearby - for example, quiescent galaxies are extremely compact, star-forming disks appear to have strange clumpy morphologies, and the dividing line between these categories starts to blur.  In this talk, I will present a simulator's perspective on these challenging observations, drawing results both from large-volume cosmological simulations (which allow us to compare and predict the statistical properties of galaxy populations) and high-resolution zoom-in simulations (which allow us to drill down on the physics governing individual systems).  I will show how the predicted variety of formation channels and evolutionary pathways taken by massive compact galaxies presents a case study on how galaxy populations evolve over time, and discuss how we can use these simulation results to inform future observational studies.  I will then turn to kinematics, showing predictions for massive galaxy rotation over time, the physics governing that rotation, and whether and how it can be used to infer dynamical mass.  The study of massive high-redshift galaxies informs some of the most pressing questions in galaxy formation today, including:  What causes galaxies to cease forming stars?  What is the physical relationship between supermassive black holes and the galaxies which host them?  Why is there a morphological/kinematic difference between star-forming and quiescent galaxies?  And how do all of these things depend on cosmic time?  The advents of JWST, LSST, and WFIRST over the next decade will help answer these questions, providing us an unprecedented view of the dynamic first few Gyrs of the Universe's history.  As I conclude, I will discuss future prospects for how high-redshift galaxy theory and simulation can anticipate and meet the challenges that these new observations will inevitably bring.


Location and Address

321 Allen Hall