The effect of a disc on the population of cuspy and cored dark matter substructures in Milky Way-like galaxies

Abstract

We use high-resolution $N$-body simulations to study the effect of a galactic disc on the dynamical evolution of dark matter substructures with orbits and structural parameters extracted from the Aquarius A-2 merger tree (Springel et al. 2008). Satellites are modelled as equilibrium $N$-body realizations of generalized Hernquist profiles with $2\times 10^6$ particles and injected in the analytical evolving host potential at $z_{\mathrm{infall}}$, defined by the peak of their mass evolution. We select all substructures with $M_{200}(z_{\mathrm{infall}})\ge 10^8{\mathrm{M}}_{\odot }$ and first pericentric distances $r_p<r_{200}$. Motivated by observations of Milky Way dwarf spheroidal galaxies, we also explore satellite models with cored dark matter profiles with a fixed core size $r_c=0.8a_s$ where $a_s$ is the Hernquist scale radius. We find that models with cuspy satellites have twice as many surviving substructures at $z=0$ than their cored counterparts, and four times as many if we only consider those on orbits with $r_p\lesssim 0.1r_{200}$. For a given profile, adding an evolving disc potential reduces the number of surviving substructures further by a factor of $\lesssim 2$ for satellites on orbits that penetrate the disc ($r_p\lesssim 20\mathrm{kpc}$). For large $r_p$, where tidal forces and the effect of the disc become negligible, the number of satellites per pericentre bin converges to similar values for all four models.

5 pages, 3 figures

References in corpus (6)

• Too big to fail? The puzzling darkness of massive Milky Way subhaloes
• A blueprint for detecting supersymmetric dark matter in the Galactic halo
• Phase-space structure in the local dark matter distribution and its signature in direct detection experiments
• The Cold Dark Matter Halos of Local Group Dwarf Spheroidals
• Early flattening of dark matter cusps in dwarf spheroidal galaxies
• The stability of stellar disks in Milky-Way sized dark matter halos

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