CAREER: Modeling the Evolution of Massive Galaxies with Enzo-E

About This Grant

The past few decades have seen tremendous advances in our understanding of galaxy formation and evolution using both observations and detailed computer simulations. However, many key questions are still not fully understood. For example, most massive elliptical galaxies, among the oldest and most massive structures in the universe and hosts of supermassive black holes (SMBH), cease forming stars and transition into passively evolving systems. While the precise mechanisms underpinning such "quenching" are unclear, SMBHs appear to play a key role by suppressing the infall of fresh gas - the raw material of star formation - from the circumgalactic medium (CGM). The PI will conduct a computer simulation of a massive galaxy's formation and evolution with spatial resolution sufficient to resolve the CGM's complex structure and the small-scale physical processes occurring there. This work will inform and complement large-scale cosmological simulations and will provide mentoring and training for three graduate students in cutting edge galaxy simulations. Undergraduate students will also be involved, and the investigator will engage in outreach to local high schools and public planetarium shows. To better understand the evolution of massive galaxies, the investigator and her group will conduct a very high- resolution numerical study using a cosmological-zoom simulation focusing on the formation of a single massive galaxy while following its evolution all the way down to the current epoch (z = 0). The major objectives of this work are to understand (1) how SMBHs form and grow in massive galaxies, (2) precisely how SMBH "feedback" leads to star formation quenching, (3) the structure and evolution the CGM, and (4) how the evolution of satellite galaxies is affected. The team will use the newly developed Enzo-E, which is a highly scalable redesign of the original Enzo code for the exascale era. They will develop a new state-of-the-art SMBH formation/feedback model, which will be added to the publicly available code and shared with the community. The proposed simulations will force enhanced refinement in the galaxy's CGM, providing unprecedented details of this major gas reservoir around massive galaxies, which likely plays a key role in regulating the fueling of both SMBHs and star formation. This research will provide insight into the complex interplay between SMBHs, the CGM, and star formation in a massive galaxy, and it will provide a framework for simulating the effects of (e.g.) cosmic rays, dust, and radiative transfer. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.