Star Formation across Galactic Environments

Abstract:

Galaxies grow by turning cold gas into stars, but what controls this process and eventually causes galaxies to stop forming stars remains an important question in astronomy. This thesis investigates how the surrounding environment of a galaxy and the movement of gas into, out of, and around galaxies regulate star formation. I combine computer simulations with observations from several major telescopes to study galaxies in different environments and stages of cosmic history. I find that both galaxy properties and their large-scale environment influence how efficiently gas forms stars. Detailed observations of a galaxy at the center of a massive galaxy cluster show how gas can cool, heat, and circulate between the galaxy and its environment. I also study a distant galaxy that has stopped forming stars and find that it contains very little gas to fuel star formation. Together, these results show that galaxy growth depends on interconnected processes operating across a wide range of physical scales.