Dr. Laura Scholz (IAC)
9 April 2025
11:30, Aula Piazzi
Abstract:
In our standard cosmological model, galaxy assembly is inherently linked to the hierarchical growth of dark matter halos, which provide the gravitational framework in which highly non-linear baryonic processes unfold. Although galaxy evolution is governed by the complex interplay between baryonic physics and halo assembly, the extent to which halo properties shape observed galaxy properties remains unclear. In this talk, I will report observational evidence indicating that baryonic properties of nearby galaxies depend on the mass of their host dark matter halos. We map galaxy ages, metallicities and star formation histories across the stellar-to-halo mass relation for SDSS central galaxies using absorption optical spectra. In addition to stellar populations, we also investigate the stellar angular momentum, star formation rates and galaxy morphology across the stellar-to-total dynamical mass relation for CALIFA galaxies. We find that the scatter of both relations correlates with these galaxy properties, which are determined by the combined role of stellar and halo/total mass. Galaxies become older, more metal-rich and less rotationally supported, form the bulk of their stars earlier on and faster, have lower star formation rates and earlier-type morphologies as their stellar mass increases (at fixed halo/total mass). Furthermore, galaxies with different total masses not only exhibit different global properties, but also show distinct age and metallicity gradients and radial profiles. We interpret our results in the context of halo evolution, with halos forming at different cosmic times driving the observed trends. Our findings indicate that dark matter halos play a key role in shaping the star formation, chemical enrichment, and assembly histories of galaxies, affecting both their spatially-integrated and -resolved properties observed at present day.