Speaker
Description
The gas cycle in and around galaxies is key to their evolution. Cosmological simulations have made enormous progress over the past decade in coming up with effective models for galaxy formation, unifying the Lambda cold dark matter cosmological model with the theory of galaxy formation. Yet, these simulations still struggle to accurately represent warm and cold gas and its cycling in space and thermodynamic state. This is a significant limitation to the predictive power of cosmological simulations since they are unable to provide predictions to emission and absorption features from these colder gas phases, e.g. in galactic outflows. In this talk, I will present a novel way to overcome this limitation without the need to explicitly resolve individual cold clouds. Using a multi-fluid approach, I will demonstrate how the unresolved interactions of cold clouds with the surrounding medium can be coarse-grained either from isolated high-resolution simulations or through fitting model parameters to observational data. I will also show how this modeling technique can resolve some of the long-standing challenges in cosmological galaxy simulations such as the self-consistent launching of outflows from the interstellar medium without the employment of numerical tricks such as hydrodynamical decoupling, burstiness or delayed cooling.
