Why Are Halo Density Profiles Stable at Formation?
نویسنده
چکیده
We analyze the physical justification of the picture proposed by Salvador-Solé et al. in these proceedings for the time evolution of the universal density profile of dark-matter halos. According to this picture, halos have at formation a stable (i.e. independent of mass and time) dimensionless density profile, the characteristic length and density scales of the profile depending on the underlying cosmogony. Subsequent evolution is driven by mass accretion onto the outskirts of halos and can be characterized simply by the increment of halo radius with time and the corresponding decrease of the critical density of the universe. We find this picture to be a reasonable good description of the expected evolution of halos in hierarchical models of structure formation.
منابع مشابه
Deriving the Nonlinear Cosmological Power Spectrum and Bispectrum from Analytic Dark Matter Halo Profiles and Mass Functions
We present an analytic model for the fully nonlinear power spectrum P and bispectrum Q of the cosmological mass density field. The model is based on physical properties of dark matter halos, with the three main model inputs being analytic halo density profiles, halo mass functions, and halo-halo spatial correlations, each of which has been well studied in the literature. We demonstrate that thi...
متن کاملHow universal are the density profiles of dark halos ?
We investigate the formation of virialized halos due to the gravitational collapse of collisionless matter using high-resolution N-body simulations. A variety of formation scenarios are studied, ranging from hierarchical clustering to monolithic radial collapse. The goal of these experiments was to study departures from the universal density profiles recently found to arise in cosmological sett...
متن کاملHow Many Galaxies Fit in a Halo? Constraints on Galaxy Formation Efficiency from Spatial Clustering
We study galaxy clustering in the framework of halo models, where gravitational clustering is described in terms of dark matter halos. At small scales, dark matter clustering statistics are dominated by halo density profiles, whereas at large scales, correlations are the result of combining non-linear perturbation theory with halo biasing. Galaxies are assumed to follow the dark matter profiles...
متن کاملWARMANDFUZZY: the halo model beyond CDM
Cold dark matter (CDM) is a well established paradigm to describe cosmological structure formation, and works extraordinarily well on large, linear, scales. Progressing further in dark matter physics requires being able to understand structure formation in the non-linear regime, both for CDM and its alternatives. This short note describes a calculation, and accompanying code, WARMANDFUZZY, inco...
متن کاملScaling Evolution of Universal Dark-matter Halo Density Profiles
Dark-matter halos show a universal density profile with a scaling such that less massive systems are typically denser. This mass-density relation is well described by a proportionality between the characteristic density of halos and the mean cosmic density at halo formation time. It has recently been shown that this proportionality could be the result of the following simple evolutionary pictur...
متن کامل