Shaw-IAU Workshops by the OAE

Modern telescopes reveal a stunning variety of galaxies across the cosmos: elegant spirals like our Milky Way, smooth ellipticals, and irregular shapes that defy easy classification. These vast systems of hundreds of billions of stars are not scattered randomly, but form an intricate cosmic web: filaments, clusters, and voids that stretch across billions of light-years. One of the central challenges of cosmology and galaxy evolution is to understand how such structure emerged from the nearly uniform conditions of the early Universe, and how processes driven by both visible and invisible components — such as dark matter, dark energy, and super massive black holes — have shaped the large-scale structure and galaxies therein over 14 billion years of cosmic evolution.

In recent decades, cosmological simulations have become indispensable tools for exploring these questions. By combining the laws of gravity, magnetohydrodynamics, and atomic physics with models for star formation, supernova explosions, and feedback from supermassive black holes, these “universes in a box” allow us to test theoretical ideas and directly compare them with astronomical observations. Thanks to advances in supercomputing and algorithmic design, simulations that once tracked only a few thousands of particles can now follow tens of billions, capturing the complex interplay between cosmic structure and the galaxies that inhabit it.

I will present results from the IllustrisTNG project, a suite of large-scale simulations that has become a benchmark for modeling the formation and evolution of galaxies, and introduce its successors such as TNG-Cluster, which follows the growth of hundreds of massive galaxy clusters. These simulations reproduce many of the observed properties of real galaxies and have revealed the crucial role of feedback from stars and black holes in regulating their growth and evolution. I will highlight how these processes shape not only the stars and gas within galaxies, and hence how galaxies evolve and interact, but also their extended environments — from the circumgalactic medium to the hot plasma that permeates galaxy clusters.