Portal de Periódicos da CAPES

Dark matter halo cores and the tidal survival of Milky Way satellites

2022; Oxford University Press; Volume: 519; Issue: 1 Linguagem: Inglês

10.1093/mnras/stac3499

1365-2966

Raphaël Errani, Julio F. Navarro, Jorge Peñarrubia, Benoît Famaey, Rodrigo Ibata,

Cosmology and Gravitation Theories

The cuspy central density profiles of cold dark matter (CDM) haloes make them highly resilient to disruption by tides. Self-interactions between dark matter particles, or the cycling of baryons, may result in the formation of a constant-density core which would make haloes more susceptible to tidal disruption. We use N-body simulations to study the evolution of NFW-like "cored" subhaloes in the tidal field of a massive host, and identify the criteria and timescales for full tidal disruption. Our results imply that the survival of Milky Way satellites places constraints on the sizes of dark matter cores. Indeed, we find that no subhaloes with cores larger than 1 per cent of their initial NFW scale radius can survive for a Hubble time on orbits with pericentres 10 Gyr ago. These results suggest that many satellites have vanishingly small core sizes, consistent with CDM cusps. The discovery of further Milky Way satellites on orbits with small pericentric radii would strengthen these conclusions and allow for stricter upper limits on the core sizes.