Radiation hydrodynamics simulations of gas removal in dwarf galaxies

Abstract

The standard lambdaCDM model of cosmology successfully reproduces the distribution of massive galaxies and clusters in the observable Universe, However, when applied to low mass galaxies, the model consistently overpredicts the number of low mass galaxy haloes that is observed in the Local Group. Previous efforts at modelling dwarf galaxies have focussed on the refinement of energetic stellar feedback models to explain the absense of gas in these objects. However, the effects of radiation on the gas dynamics has not yet been properly discussed, mostly given its technical difficulties. We propose to improve our understanding of the formation of low mass isolated dwarf galaxies by including an accurate, on-the-fly treatment of photoionisation that properly takes into account the propagation and geometrical shielding of photoionising radiation, both from internal young stellar objects and an external UV background field. Our goal is to compare the effects of radiation on the energy budget of baryonic mass around low-mass galaxy haloes of the early Universe. (AU)