The phase-space structure of tidally stripped halos

Abstract

We propose a new method for generating equilibrium models of spherical systems of collisionless particles that are finite in extent, but whose central regions resemble dark matter halos from cosmological simulations. This method involves iteratively removing unbound particles from a Navarro-Frenk-White profile truncated sharply at some radius. The resulting models are extremely stable, and thus provide a good starting point for N-body simulations of isolated halos. We provide a code to generate such models for NFW and a variety of other common density profiles. We then develop an analytic approximation to this truncated distribution function. Our method proceeds by analogy with the King model, truncating and shifting the original distribution function of an infinitely extended Navarro-Frenk-White profile in energy space. We show that the density profiles of our models closely resemble the tidally truncated density profiles seen previously in studies of satellite evolution. Pursuing this analogy further with a series of simulations of tidal mass loss, we find that our models provide a good approximation to the full distribution function of tidally stripped systems, thus allowing theoretically motivated phase-space calculations for such systems.

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Cited by in corpus (10)

• Disruption of Dark Matter Substructure: Fact or Fiction?
• The tidal evolution of dark matter substructure -- I. Subhalo density profiles
• Phase-space structure of cold dark matter halos inside splashback: multi-stream flows and self-similar solution
• Evolution of subhalo orbits in a smoothly-growing host halo potential
• A universal model for the evolution of tidally stripped systems
• The Assembly of the Virgo Cluster, Traced by its Galaxy Halos
• The Boosted Potential
• Self-consistent dynamical models with a finite extent -- III. Truncated power-law spheres
• Magnetic field and kinetic helicity evolution in simulations of interacting disk galaxies
• A dynamics-based density profile for dark haloes. I. Algorithm and basic results