The spherical collapse model with shell crossing

Abstract

In this work, we study the formation and evolution of dark matter halos by means of the spherical infall model with shell-crossing. We present a framework to tackle this effect properly based on the numerical follow-up, with time, of that individual shell of matter that contains always the same fraction of mass with respect to the total mass. In this first step, we do not include angular momentum, velocity dispersion or triaxiality. Within this framework - named as the Spherical Shell Tracker (SST) - we investigate the dependence of the evolution of the halo with virial mass, with the adopted mass fraction of the shell, and for different cosmologies. We find that our results are very sensitive to a variation of the halo virial mass or the mass fraction of the shell that we consider. However, we obtain a negligible dependence on cosmology. Furthermore, we show that the effect of shell-crossing plays a crucial role in the way that the halo reaches the stabilization in radius and the virial equilibrium. We find that the values currently adopted in the literature for the actual density contrast at the moment of virialization, delta_vir, may not be accurate enough. In this context, we stress the problems related to the definition of a virial mass and a virial radius for the halo. The question of whether the results found here may be obtained by tracking the shells with an analytic approximation remains to be explored.

15 pages, 4 figures, 9 tables, replaced to match the published MNRAS version

References in corpus (30)

• A Universal Density Profile from Hierarchical Clustering
• The Structure of Cold Dark Matter Halos
• Statistical Properties of X-ray Clusters: Analytic and Numerical Comparisons
• Mass function of dark matter halos
• Cold collapse and the core catastrophe
• Using the Evolution of Clusters to Constrain Omega
• An excursion set model of hierarchical clustering: Ellipsoidal collapse and the moving barrier
• Resolving the Structure of Cold Dark Matter Halos
• Merger rates in hierarchical models of galaxy formation. II: Comparison with N-body simulations
• The Structure of Dark Matter Haloes in Hierarchical Clustering Models
• Resolving the Structure of Cold Dark Matter Halos II
• Density Profiles of Dark Matter Halo are not Universal
• On Formation and Evolution of Disk Galaxies: Cosmological Initial Conditions and the Gravitational Collapse
• On the physical origin of dark matter density profiles
• How far do they go? The outer structure of dark matter halos
• The structure of dark matter halos in hierarchical clustering theories
• On the origin of cold dark matter halo density profiles
• Dependence of the Inner DM Profile on the Halo Mass
• Mass growth and density profiles of dark matter halos in hierarchical clustering
• Self-similar spherical collapse with non-radial motions
• A Model For Infall Around Virialized Halos
• Empirical Models for Dark Matter Halos. III. The Kormendy relation and the log(rho_e)-log(R_e) relation
• Modelling the Nonlinear Gravitational Clustering in the Expanding Universe
• Density profiles in a spherical infall model with non-radial motions
• Formation of cuspy density profiles - a generic feature of collisionless gravitational collapse
• On the Origin of the Inner Structure of Halos
• Universal profile of dark matter halos and the spherical infall model
• On an Analytical Framework for Voids: Their abundances, density profiles and local mass functions
• Detailed theoretical predictions of the outskirts of dark matter halos
• Understanding the Equilibrium Structure of CDM Halos

Cited by in corpus (9)

• Formation and evolution of galaxy dark matter halos and their substructure
• The splashback radius of halos from particle dynamics. II. Dependence on mass, accretion rate, redshift, and cosmology
• Characterization of Dark-Matter-induced anisotropies in the diffuse gamma-ray background
• Resolving Small-Scale Dark Matter Structures Using Multi-Source Indirect Detection
• Structure Formation, Backreaction and Weak Gravitational Fields
• The Averaging Problem in Cosmology
• Simulation studies of dark energy clustering induced by the formation of dark matter halos
• Angular momentum in cluster Spherical Collapse Model
• Halo Models of Large Scale Structure and Reliability of Cosmological N-Body Simulations