Annalisa Pillepich: Universe(s) in a box: simulating galaxies to connect theory and observations

Speaker:  Annalisa Pillepich (MPA Heidelberg)

Title: Universe(s) in a box: simulating galaxies to connect theory and observations

Abstract:
Over the past decade, cosmological simulations have become a cornerstone of theoretical astrophysics — powerful “universes in a box” that connect fundamental physics and our understanding of the Universe as a whole to the galaxies and structures observed across cosmic time. These simulations combine the laws of gravity, magneto-hydrodynamics, and gas and atomic physics with models for star formation, supernova explosions, and feedback from supermassive black holes, enabling direct links between physical theory and astronomical observations. I will discuss the IllustrisTNG project, a suite of large-volume simulations that has become a benchmark for modeling the formation and evolution of galaxies, and present some of its successors, such as TNG-Cluster, which follows the growth of hundreds of massive galaxy clusters. I will highlight a few key discoveries enabled by these simulations, particularly the tight interplay between feedback from the innermost regions of galaxies and the thermodynamical, chemical, and kinematic properties of the gas in their surroundings — from the circumgalactic medium to the hot plasma of galaxy clusters. Finally, I will discuss how new techniques, including forward modeling, machine learning, and sub-parsec resolution simulations, are opening a path toward connecting the physics of individual stars and the interstellar medium to the formation of galaxies in the full cosmological context, as well as the use of galaxies, groups, and clusters as cosmological probes.