Self-Similar Solutions of Triaxial Dark Matter Halos

Abstract

We investigate the collapse and internal structure of dark matter halos. We consider halo formation from initially scale-free perturbations, for which gravitational collapse is self-similar. Fillmore and Goldreich (1984) and Bertschinger (1985) solved the one dimensional (i.e. spherically symmetric) case. We generalize their results by formulating the three dimensional self-similar equations. We solve the equations numerically and analyze the similarity solutions in detail, focusing on the internal density profiles of the collapsed halos. By decomposing the total density into subprofiles of particles that collapse coevally, we identify two effects as the main determinants of the internal density structure of halos: adiabatic contraction and the shape of a subprofile shortly after collapse; the latter largely reflects the triaxiality of the subprofile. We develop a simple model that describes the results of our 3D simulations. In a companion paper, we apply this model to more realistic cosmological fluctuations, and thereby explain the origin of the nearly universal (NFW-like) density profiles found in N-body simulations.

corresponds to version published in ApJ

References in corpus (4)

• The redshift dependence of the structure of massive LCDM halos
• The Caustic Ring Model of the Milky Way Halo
• Secondary infall and dark matter haloes
• Self-Similar Spherical Collapse with Tidal Torque

Cited by in corpus (19)

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• Don't cross the streams: caustics from Fuzzy Dark Matter
• Phase-space structure of protohalos: Vlasov versus Particle-Mesh
• The splashback radius in symmetron gravity
• The Origin of Dark Matter Halo Profiles
• Phase-space structure of cold dark matter halos inside splashback: multi-stream flows and self-similar solution
• Insights into the origin of halo mass profiles from machine learning
• Dark matter halo's and self similarity
• Evolution of subhalo orbits in a smoothly-growing host halo potential
• The Supersonic Project: The Early Evolutionary Path of SIGOs
• Universal multi-stream radial structures of cold dark matter halos
• Dark matter halo dynamics in 2D Vlasov Simulations: a self-similar approach
• Iterative mean-field approach to the spherical collapse of dark matter halos
• Connecting galaxy evolution in clusters with their radial profiles and phase space distribution: results from the IllustrisTNG hydrodynamical simulations
• A dynamics-based density profile for dark haloes. I. Algorithm and basic results
• Self-similarity of the mass distribution in rich galaxy clusters up z~1 tracked with weak lensing