Simulating the First Galaxies: Discs & Clusters

Floor van Donkelaar (University of Cambridge)

Recent observations with JWST have revealed that galaxies in the early Universe are often surprisingly clumpy, with some already hosting well-developed discs and extremely compact stellar systems. But how did these structures form so early, and what role did they play in the evolution of their galaxies?

In this talk, I will use numerical simulations to explore the formation of galactic discs and stellar clusters in the early Universe. I will discuss how the gas-rich and turbulent conditions of young galaxies can lead to disc instabilities, fragmentation, and the formation of dense stellar clusters, some of which resemble those now observed with JWST. These dense environments may also provide favorable conditions for the formation of black hole seeds. However, not all clusters form within galactic discs. I will introduce the "Cosmic Wallflowers", compact stellar clusters that form in the gas filaments surrounding galaxies, and show how their internal dynamics can provide clues about their formation environment. Finally, I will explore how feedback can change the distribution and evolution of clumps around young galaxies.

Together, these results highlight the different ways in which stellar clusters can form and evolve, and their potential role in shaping the first galaxies.