A Universal Density Profile from Hierarchical Clustering
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In this article, the authors used high-resolution N-body simulations to study the equilibrium density profiles of dark matter halos in hierarchically clustering universes, and they found that all such profiles have the same shape, independent of the halo mass, the initial density fluctuation spectrum, and the values of the cosmological parameters.Abstract:
We use high-resolution N-body simulations to study the equilibrium density profiles of dark matter halos in hierarchically clustering universes. We find that all such profiles have the same shape, independent of the halo mass, the initial density fluctuation spectrum, and the values of the cosmological parameters. Spherically averaged equilibrium profiles are well fitted over two decades in radius by a simple formula originally proposed to describe the structure of galaxy clusters in a cold dark matter universe. In any particular cosmology, the two scale parameters of the fit, the halo mass and its characteristic density, are strongly correlated. Low-mass halos are significantly denser than more massive systems, a correlation that reflects the higher collapse redshift of small halos. The characteristic density of an equilibrium halo is proportional to the density of the universe at the time it was assembled. A suitable definition of this assembly time allows the same proportionality constant to be used for all the cosmologies that we have tested. We compare our results with previous work on halo density profiles and show that there is good agreement. We also provide a step-by-step analytic procedure, based on the Press-Schechter formalism, that allows accurate equilibrium profiles to be calculated as a function of mass in any hierarchical model.read more
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References
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Journal ArticleDOI
The Structure of cold dark matter halos
TL;DR: In this article, high-resolution N-body simulations show that the density profiles of dark matter halos formed in the standard CDM cosmogony can be fit accurately by scaling a simple universal profile.
Journal ArticleDOI
On the Infall of Matter into Clusters of Galaxies and Some Effects on Their Evolution
James E. Gunn,J. Richard Gott +1 more
Journal ArticleDOI
An Analytical Model for Spherical Galaxies and Bulges
TL;DR: In this article, a modele de masse for les galaxies elliptiques, which approche la loi R 1/4 de Vaucouleur, is developpe.
Journal ArticleDOI
Merger rates in hierarchical models of galaxy formation
Cedric G. Lacey,Shaun Cole +1 more
TL;DR: In this article, an analytical description of the merging of virialized haloes is presented, which is applicable to any hierarchical model in which structure grows via gravitational instability, and the dependence of the merger rate on halo mass, epoch, the spectrum of initial density fluctuations and the density parameter Ω 0 is explicitly quantified.