Fornax globular cluster distributions: implications for the cusp-core problem

Abstract

We re-investigate the Fornax cusp-core problem using observational results on the spatial and mass distributions of globular clusters (GCs) in order to put constraints on the dark matter profile. We model Fornax using high-resolution N-body simulations with entirely live systems, i.e. self-gravitating systems composed of stars and dark matter, which account correctly for dynamical friction and tidal effects between Fornax and the globular clusters. We test two alternative hypotheses, which are a cored and a cuspy halo for Fornax by exploring a reasonable range of initial conditions on globular clusters. For Fornax cored dark matter halo, we derive a lower limit on the core size of $r_{c}\gtrsim$ 0.5 kpc. Contrary to many previous works, we show also that for different initial conditions, a cuspy halo is not ruled out in our simulations based on observations of Fornax globular clusters.