Cold dark matter subhaloes at arbitrarily low masses

Understand

A defining prediction of the cold dark matter (CDM) cosmological model is the existence of a very large population of low mass haloes, down to planet-size masses.

• However, their fate as they are accreted onto haloes many orders of magnitude more massive remains fundamentally uncertain.
• A number of numerical explorations have found subhaloes to be very resilient to tides, but resolution limits make it difficult to explore tidal evolution at arbitrarily low masses.
• What are the structural properties of heavily stripped subhaloes? Do tidal effects destroy low-mass CDM subhaloes? Here we focus on cosmologically motivated subhaloes orbiting CDM hosts, and show that subhaloes of any initial mass can be stripped to arbitrarily small mass fractions.