The Orbital Evolution Induced by Baryonic Condensation in Triaxial Halos

Understand

Using spectral methods, we analyse the orbital structure of prolate/triaxial dark matter (DM) halos in N-body simulations to understand the processes that drive the evolution of shapes of DM halos and elliptical galaxies in which central masses are grown.

• A longstanding issue is whether the change in the shapes of DM halos is the result of chaotic scattering of box orbits, or whether they change shape adiabatically in response to the evolving galactic potential.
• We use orbital frequencies to classify orbits, to quantify orbital shapes, and to identify resonant orbits and chaotic orbits.
• The frequency-based method overcomes the limitations of Lyapunov exponents which are sensitive to numerical discreteness effects.