Disruption of Dark Matter Substructure: Fact or Fiction?

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Accurately predicting the demographics of dark matter (DM) substructure is of paramount importance for many fields of astrophysics, including gravitational lensing, galaxy evolution, halo occupation modeling, and constraining the nature of dark matter.

• Because of its strongly non-linear nature, DM substructure is typically modeled using N-body simulations, which reveal that large fractions of DM subhaloes undergo complete disruption.
• In this paper we use both analytical estimates and idealized numerical simulations to investigate whether this disruption is mainly physical, due to tidal heating and stripping, or numerical (i.e., artificial).
• We show that, contrary to naive expectation, subhaloes that experience a tidal shock $\Delta E$ that exceeds the subhalo's binding energy, $|E_{\rm b}|$, do not undergo disruption, even when $\Delta E/|E_{\rm b}|$ is as large as 100.