Astroparticle Seminar

The EAGLE project: Simulating the joint evolution of galaxies and dark matter in a large cosmological volume

Matthieu Schaller

Durham University

The EAGLE (Evolution and Assembly of GaLaxies in their Environment) project is a suite of hydrodynamical simulations that follow the formation of galaxies, black holes and dark matter in representative volumes (Schaye+2014 arxiv:1407.7040). Our main simulation is one of the first of its kind to reproduce a whole series of properties of the observed galaxy population such as their abundance, sizes, luminosities, colours, star formation rates and morphologies. EAGLE hence constitutes a valuable new resource for studies of galaxy formation.

One of the robust predictions from cold dark matter simulations is that the dark matter (DM) within halos is well described by a Navarro-Frenk-White (NFW) density profile and observations of galaxy clusters and local dwarf galaxies will soon be able to test these predictions. The presence of baryons modifies this profile due to the violent processes that accompany star formation and super massive black hole evolution. Nevertheless, we show that the DM follows closely the NFW density profile at radii larger than 5% of the halo virial radius (Schaller+2014a arxiv:1409.8617). The behaviour in the inner 5% is, however, significantly different and the changes seen will impact direct and indirect dark matter detection experiments.

In this talk, I will introduce cosmological simulations and the EAGLE project focusing on the key elements that make our simulation special and will then focus on the properties of the dark matter distribution. Movies and images can be found here.