Small-scale galaxy clustering in the EAGLE simulation

Abstract

We study present-day galaxy clustering in the EAGLE cosmological hydrodynamical simulation. EAGLE's galaxy formation parameters were calibrated to reproduce the redshift z = 0.1 galaxy stellar mass function, and the simulation also reproduces galaxy colours well. The simulation volume is too small to correctly sample large-scale fluctuations and we therefore concentrate on scales smaller than a few mega parsecs.We find very good agreement with observed clustering measurements from the Galaxy And Mass Assembly (GAMA) survey, when galaxies are binned by stellar mass, colour or luminosity. However, low-mass red galaxies are clustered too strongly, which is at least partly due to limited numerical resolution. Apart from this limitation, we conclude that EAGLE galaxies inhabit similar dark matter haloes as observed GAMA galaxies, and that the radial distribution of satellite galaxies, as a function of stellar mass and colour, is similar to that observed as well.