The behaviour of shape and velocity anisotropy in dark matter haloes

Understand

Dark matter haloes from cosmological N-body simulations typically have triaxial shapes and anisotropic velocity distributions.

• Recently it has been shown that the velocity anisotropy, beta, of cosmological haloes and major merger remnants depends on direction in such a way that beta is largest along the major axis and smallest along the minor axis.
• In this work we use a wide range of non-cosmological N-body simulations to examine halo shapes and direction-dependence of velocity anisotropy profiles.
• For each of our simulated haloes we define 48 cones pointing in different directions, and from the particles inside each cone we compute velocity anisotropy profiles.