Contributed Talk - Splinter Computation

Friday, 25 September 2020, 16:36   (virtual room B)

The art of sub-resolution modelling

Milena Valentini (1,2), K. Dolag (1,2), S. Borgani (3), G. Murante (3), A. Bressan (4), et al.
1- USM/LMU 2- Excellence Cluster ORIGINS 3- INAF/OATs 4- SISSA

Cosmological simulations have to resort to sub-resolution models to capture the results of processes occurring below their resolution limit. The impact of different sub-resolution prescriptions accounting for the same physical process on final results is striking, although often overlooked. I investigate the impact of galactic outflow modelling on the formation and evolution of a disc galaxy, by performing a suite of cosmological simulations with initial conditions of a Milky Way-sized halo. In this talk, I will show how sensitive the general properties of the simulated galaxy are to the way in which stellar feedback triggered outflows are implemented, comparing results obtained by adopting different galactic outflow models. I will discuss the key requirements that a feedback model must have to be successful in producing a galaxy with an extended disc component, and the crucial importance of galactic outflows in reproducing observational features of present-day disc galaxies.  I will also introduce a new methodology to generate synthetic stars from star particles in cosmological simulations. This algorithm takes properties of star particles from simulations as input and allows to obtain a catalogue of mock stars, provided with photometric properties. The goal of this method is to translate the populations of star particles of a simulation into stellar populations, thereby enabling a direct and accurate comparison with observations. This technique will be of paramount importance with ongoing survey data releases (e.g. GAIA and surveys of resolved stellar populations).