Universal profile of dark matter halos and the spherical infall model

Abstract

I propose a modification of the spherical infall model for the evolution of density fluctuations with initially Gaussian probability distribution and scale-free power spectra in Einstein-de Sitter universe as developed by Hoffman & Shaham. I introduce a generalized form of the initial density distribution around an overdense region and cut it off at half the inter-peak separation accounting in this way for the presence of the neighbouring fluctuations. Contrary to the original predictions of Hoffman & Shaham the resulting density profiles within virial radii no longer have power-law shape but their steepness increases with distance. The profiles of halos of galactic mass are well fitted by the universal profile formula of changing slope obtained as a result of N-body simulations by Navarro, Frenk & White. The trend of steeper profiles for smaller masses and higher spectral indices is also reproduced. The agreement between the model and simulations is better for smaller masses and lower spectral indices which suggests that galaxies form mainly by accretion while formation of clusters involves merging.

12 pages + 5 figures, significantly revised (collapse factor properly calculated, agreement with N-body simulations dramatically improved), accepted for publication in MNRAS

References in corpus (6)

• The Cores of Dark Matter Dominated Galaxies: theory vs. observations
• The Average Mass Profile of Galaxy Clusters
• On Formation and Evolution of Disk Galaxies: Cosmological Initial Conditions and the Gravitational Collapse
• Mass growth and density profiles of dark matter halos in hierarchical clustering
• Merger vs. Accretion and the Structure of Dark Matter Halos
• Evolution of peaks in weakly nonlinear density field and dark halo profiles

Cited by in corpus (24)

• The Evolution of X-ray Clusters and the Entropy of the Intra Cluster Medium
• Properties of spherical galaxies and clusters with an NFW density profile
• Structure of Dark Matter Halos From Hierarchical Clustering
• On the physical origin of dark matter density profiles
• Dark matter distribution in dwarf spheroidal galaxies
• The Cusp/Core problem and the Secondary Infall Model
• Investigating the Origins of Dark Matter Halo Density Profiles
• Self-similar spherical collapse with non-radial motions
• \textsc{CompaSO}: A new halo finder for competitive assignment to spherical overdensities
• Density profiles in a spherical infall model with non-radial motions
• Formation of cuspy density profiles - a generic feature of collisionless gravitational collapse
• What sets the central structure of dark matter haloes?
• On the Origin of the Inner Structure of Halos
• Theoretical dark matter halo density profile
• Scalelengths in Dark Matter Halos
• Density Profiles of Collisionless Equilibria. II. Anisotropic Spherical Systems
• Phase Space dynamics of triaxial collapse: Joint density-velocity evolution
• Detailed theoretical predictions of the outskirts of dark matter halos
• Extended Press-Schechter theory and the density profiles of dark matter haloes
• The spherical collapse model with shell crossing
• Neutrino Mass Limit from Galaxy Cluster Number Density Evolution
• Velocity Distributions from Nonextensive Thermodynamics
• Correlations in the matter distribution in CLASH galaxy clusters
• A dynamics-based density profile for dark haloes. I. Algorithm and basic results