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Cosmology
cosmology seminar: Shy Genel (CfA) & Robert Feldmann (UCB)
Shy Genel - Title: Galaxy formation on a moving mesh: moving towards a realistic simulated Universe Abstract: Galaxy formation is a complex process that is notoriously hard to model due to both the large variety of physical processes that are involved and the huge dynamic range they encompass. I will describe a comprehensive set of galaxy formation physics recently implemented in the moving-mesh code AREPO that is suited for cosmological simulations that resolve scales of hundreds of parsecs, which includes the formation and evolution of stars and black holes, and various forms of feedback exerted by those processes on the gas. The galaxies that form in cosmological simulations run with this physics implementation, both simulations on scales of ~100Mpc and zoom-in ones, resemble observed galaxy populations, at low and high redshift, in a large variety of aspects. Robert Feldmann - Title: Star formation laws and their role in galaxy evolution Abstract: Empirical relations connecting star formation and the interstellar medium form the basis of many theoretical models of galaxy evolution. Observations of the cosmic star formation history, the mass-metallicity relation, and the gas fractions of galaxies put stringent constraints on the actual functional relationship between star formation and the gas reservoir of galaxies. I will show that adopting a linear star formation law with a gas consumption time as observed in nearby galaxies results in good agreement with observations across all cosmic epochs, suggesting a near universality of the star formation law. I will further outline a novel equilibrium picture of galaxy evolution which shows that average galaxy properties are determined by the competition between gas consumption (set by the star formation law) and matter accretion (set by gravity). I will argue that galaxy evolution can largely be understood to be a consequence of the modulation of the matter accretion rate with cosmic time.
