The star-by-star formation of the smallest galaxies

Eric Andersson (American Museum of Natural History)

July 07, 2025

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Abstract: Modern simulations of the galaxy formation process now routinely reach the scales necessary to self-consistently capture the internal structure of molecular clouds while simultaneously accounting for galactic-scale gas flows. This has led to significant theoretical progress, particularly concerning star formation and stellar feedback. Galaxy formation theory has thus entered an era of highly precise modeling, with many predictions being robust to significant model changes. In the context of the project Engineering Dwarfs at Galaxy formation’s Edge (EDGE), I will review recent advances in star-by-star modeling and lessons learned from models of dwarf galaxies. I will present the latest generation of galaxy simulations, where individual stars are resolved objects, even in cosmological environments. These star-by-star simulations emphasize stellar dynamics and stellar evolution theory as key aspects of galaxy formation theory. Furthermore, with individual stars being directly accessible in our simulations we can directly derive observables. I will show how this can be applied to guide the next-generation observatories and further constrain galaxy formation theory.