Tracking the orbit of unresolved subhalos for semi-analytic models

Understand

We present a model to track the orbital evolution of "unresolved subhaloes" (USHs) in cosmological simulations.

• USHs are subhaloes that are no longer distinguished by halo finders as self-bound overdensities within their larger host system due to limited mass resolution.
• These subhaloes would host "orphan galaxies" in semi-analytic models of galaxy formation and evolution (SAMs).
• Predicting the evolution of the phase-space components of USHs is crucial for the adequate modelling of environmental processes, interactions and mergers implemented in SAMs that affect the baryonic properties of orphan satellites.