2016MNRAS.462.3628R

The shape and diversity of dwarf galaxy rotation curves is at apparent odds with dark matter halos in a Λ Cold Dark Matter (ΛCDM) cosmology. We use mock data from isolated dwarf galaxy simulations to show that this owes to three main effects. Firstly, stellar feedback heats dark matter, leading to a `CORENFWdark matter density profile with a slowly rising rotation curve. Secondly, if close to a recent starburst, large H I bubbles push the rotation curve out of equilibrium, deforming the rotation curve shape. Thirdly, when galaxies are viewed near face-on, their best fit inclination is biased high. This can lead to a very shallow rotation curve that falsely implies a large dark matter core. All three problems can be avoided, however, by a combination of improved mass models and a careful selection of target galaxies. Fitting our CORENFW model to mock rotation curve data, we show that we can recover the rotation curve shape, dark matter halo mass M₂₀₀ and concentration parameter c within our quoted uncertainties.