"From Atoms and Molecules to Galaxy Formation"

Abstract:

Observations of the high-redshift Universe are reshaping our understanding of how the first stars and galaxies formed. In this talk, I will show how the formation of primordial structures can be modelled by linking microphysical processes to cosmological scales and how these predictions compare with the latest observations from ALMA and JWST.

I will present results from ColdSIM, a suite of hydrodynamical simulations that follows the evolution of cold cosmic gas with non-equilibrium atomic and molecular chemistry, radiative cooling, star formation, stellar feedback, and metal enrichment from SNII, AGB stars, and SNIa. These simulations provide self-consistent predictions for galaxy stellar masses, UV luminosities, and the brightest submillimeter cooling lines, including [C II] 158 μm and [O I] 63 and 145 μm.

By combining simulations with recent observations, I will explore the physical properties of galaxies at z > 5, including their HI and H₂ content, star formation rates from Pop III and Pop II-I stars, gas depletion timescales, star formation efficiencies, and mass-metallicity relations. This comparison provides new insights into the physical processes that drove the formation and early evolution of the first cosmic structures.