1:00-2:00pm ET
Lights Out: Physical Views of Galaxy Quenching
Speaker
Lori Porter
Abstract
The shutdown of star formation, or quenching, is one of the most important transitions in a galaxy’s lifetime. It gives rise to the observed galaxy color bimodality, yet the physical processes responsible for quenching remain incompletely understood. The persistence of large cold gas reservoirs in many quenched galaxies suggests that galaxies can stop forming stars without fully exhausting or expelling their fuel supply. In this talk, I will review recent work investigating how galactic dynamics regulate star formation, with a particular focus on the role of shear. Recent simulations and star formation models indicate that strong differential rotation can stabilize dense gas against collapse in bulge-dominated galaxies, reducing star formation efficiency through a process known as dynamical suppression. This framework offers a natural explanation for why some galaxies remain gas-rich but quiescent, and may result in elevated Coriolis forces. Finally, I will discuss how future observatories such as HWO will provide the spatial resolution and sensitivity needed to connect gas kinematics and star formation across cosmic time, helping to reveal the physical mechanisms that drive galaxies from active growth to quiescence.