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We make a simple analytical study of radial profiles of dark matter structures, with special attention to the question of the central radial density profile. We let our theoretical assumptions be guided by results from numerical…

Astrophysics · Physics 2009-11-10 Steen H. Hansen

We study the mass, velocity dispersion, and anisotropy profiles of $\Lambda$CDM halos using a suite of N-body simulations of unprecedented numerical resolution (the {\it Aquarius Project}). Our analysis confirms a number of results claimed…

Cosmological N-body simulations indicate that the spherically-averaged density profiles of cold dark matter halos are accurately described by Einasto profiles, where the logarithmic slope is a power-law of adjustable exponent, \gamma…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-18 Aaron D. Ludlow , Julio F. Navarro , Michael Boylan-Kolchin , Volker Springel , Adrian Jenkins , Carlos S. Frenk , Simon D. M. White

We report statistical results for dark matter (DM) velocity anisotropy, \beta, from a sample of some 6000 cluster-size halos (at redshift zero) identified in a \Lambda CDM hydrodynamical adaptive mesh refinement simulation performed with…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 Doron Lemze , Rick Wagner , Yoel Rephaeli , Sharon Sadeh , Michael L. Norman , Rennan Barkana , Tom Broadhurst , Holland Ford , Marc Postman

Adaptive SPH and N-body simulations were carried out to study the evolution of the equilibrium structure of dark matter halos that result from the gravitational instability and fragmentation of cosmological pancakes. Such halos resemble…

Astrophysics · Physics 2009-11-06 Marcelo Alvarez , Paul R. Shapiro , Hugo Martel

Properties of dark matter halos are reviewed. Taken from different publications, we present results on (1) the mass and velocity functions, (2) density and velocity profiles, and (3) concentration of halos. In the range of radii…

Astrophysics · Physics 2007-05-23 Anatoly Klypin

Galaxies show different halo scaling relations such as the Radial Acceleration Relation, the Mass Discrepancy Acceleration Relation (MDAR) or the dark matter Surface Density Relation (SDR). At difference with traditional studies using…

Cosmology and Nongalactic Astrophysics · Physics 2023-03-08 A. Krut , C. R. Argüelles , P. -H. Chavanis , J. A. Rueda , R. Ruffini

We present new constraints on the density profiles of dark matter (DM) halos in seven nearby dwarf galaxies from measurements of their integrated stellar light and gas kinematics. The gas kinematics of low mass galaxies frequently suggest…

I report on recent progress in our understanding of the structure of CDM halos, and in particular of the inner mass profile of galaxy-sized systems. Numerical simulations have consistently shown that the density profiles of CDM halos…

Astrophysics · Physics 2007-05-23 Julio F. Navarro

We demonstrate that all properties of the hot X-ray emitting gas in galaxy clusters are completely determined by the underlying dark matter (DM) structure. Apart from the standard conditions of spherical symmetry and hydrostatic equilibrium…

Cosmology and Nongalactic Astrophysics · Physics 2012-03-06 Teddy F. Frederiksen , Steen H. Hansen , Ole Host , Marco Roncadelli

We use a set of high-resolution simulations of scale-free Einstein-de Sitter cosmologies to investigate the logarithmic slope of the phase-space density profile $Q(r) = \rho(r)/\sigma^3(r)$ of dark matter (DM) haloes. The initial conditions…

Astrophysics · Physics 2009-11-13 Steffen R. Knollmann , Alexander Knebe , Yehuda Hoffman

We explore similarities in the luminosity distribution of early type galaxies and the mass profiles of LCDM halos. The spatial structure of these systems may be accurately described by a simple law where the logarithmic slope of the…

Astrophysics · Physics 2009-11-10 David Merritt , Julio F. Navarro , Aaron Ludlow , Adrian Jenkins

We have derived the first, fully-cosmological, similarity solutions for CDM halo formation in the presence of nongravitational collisionality, which provides an analytical theory of the effect of the self-interacting dark matter (SIDM)…

Astrophysics · Physics 2009-11-10 Kyungjin Ahn , Paul R. Shapiro

We use the universal mass accretion history recently reported for simulations of halo formation in the cold dark matter model (CDM) to analyze the formation and growth of a single halo. We derive the time-dependent density profile three…

Astrophysics · Physics 2007-05-23 Marcelo A. Alvarez , Kyungjin Ahn , Paul R. Shapiro

(Abridged) Using high-resolution cosmological N-body simulations, we study how the density profiles of dark matter halos are affected by the filtering of the density power spectrum below a given scale length and by the introduction of a…

Astrophysics · Physics 2009-09-25 V. Avila-Reese , P. Colin , O. Valenzuela , E. D'Onghia , C. Firmani

Simulated dark matter profiles are often modelled as a `NFW' density profile rather than a single power law. Recently, attention has turned to the rather rigorous power-law behaviour exhibited by the `pseudo phase-space density' of the dark…

Astrophysics · Physics 2008-11-26 R. N. Henriksen

High resolution N-body simulations have all but converged on a common empirical form for the shape of the density profiles of halos, but the full understanding of the underlying physics of halo formation has eluded them so far. We…

N-body simulations of dark matter halos show that the density profiles of halos behave as $\rho(r)\propto r^{-\alpha(r)}$, where the density logarithmic slope $\alpha \simeq 1\sim1.5$ in the center and $\alpha \simeq 3\sim 4$ in the outer…

Astrophysics · Physics 2015-05-13 Ding Ma , Ping He

Current data suggest that the central mass densities $\rho_0$ and phase-space densities $Q\equiv\rho_0/\sigma_V^3$ of cosmological halos in the present universe are correlated with their velocity dispersions $\sigma_V$ over a very wide…

Astrophysics · Physics 2009-11-06 Paul R. Shapiro , Ilian T. Iliev

Elliptical galaxies are modelled as Sersic luminosity distributions with density profiles (DPs) for the total mass adopted from the DPs of haloes within dissipationless LambdaCDM N-body simulations. Ellipticals turn out to be inconsistent…

Astrophysics · Physics 2014-12-15 Gary A. Mamon , Ewa L. Lokas