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We examine the coarse-grained phase-space density profiles of a set of recent, high-resolution simulations of galaxy-sized Cold Dark Matter (CDM) halos. Over two and a half decades in radius the phase-space density closely follows a…

Astrophysics · Physics 2009-11-06 James E. Taylor , Julio F. Navarro

We present density profiles, that are solutions of the spherical Jeans equation, derived under the following two assumptions: (i) the coarse grained phase-density follows a power-law of radius, rho/(sigma^3) proportional to r^{-alpha}, and…

Astrophysics · Physics 2009-11-07 Nicolaos Hiotelis

It has long been realized that dark matter halos formed in cosmological N-body simulations are characterized by density profiles rho(r) that, when suitably scaled, have similar shapes. Additionally, combining the density and velocity…

Astrophysics · Physics 2010-11-05 Eric I. Barnes , Liliya L. R. Williams , Arif Babul , Julianne J. Dalcanton

We identify a universal relation between the radial density slope \alpha (r) and the velocity anisotropy \beta (r) for equilibrated structures. This relation holds for a variety of systems, including disk galaxy mergers, spherical…

Astrophysics · Physics 2007-05-23 Steen H. Hansen , Ben Moore

We show that the two basic assumptions of the model recently proposed by Manrique and coworkers for the universal density profile of cold dark matter (CDM) halos, namely that these objects grow inside out in periods of smooth accretion and…

One can solve the Jeans equation analytically for equilibrated dark matter structures, once given two pieces of input from numerical simulations. These inputs are 1) a connection between phase-space density and radius, and 2) a connection…

Astrophysics · Physics 2009-11-13 Steen H. Hansen , Joachim Stadel

I report recent results of numerical simulations designed to study the inner structure of Cold Dark Matter (CDM) halos. This work confirms the proposal of Navarro, Frenk & White (NFW) that the shape of LambdaCDM halo mass profiles differs…

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

The evolution of the phase-space density profile in dark matter (DM) halos is investigated by means of constrained simulations, designed to control the merging history of a given DM halo. Halos evolve through a series of quiescent phases of…

Astrophysics · Physics 2009-11-13 Yehuda Hoffman , Emilio Romano-Diaz , Isaac Shlosman , Clayton Heller

We use techniques from nonparametric function estimation theory to extract the density profiles, and their derivatives, from a set of N-body dark matter halos. We consider halos generated from LCDM simulations of gravitational clustering,…

Astrophysics · Physics 2012-04-26 David Merritt , Alister W. Graham , Ben Moore , Juerg Diemand , Balsa Terzic

One can solve the Jeans equation analytically for equilibrated dark matter structures, once given two pieces of input from numerical simulations. These inputs are 1) a connection between phase-space density and radius, and 2) a connection…

Astrophysics · Physics 2015-06-24 Steen H. Hansen , Ben Moore , Joachim Stadel

We investigate, using the spherical Jeans equation, self-gravitating dynamical equilibria satisfying a relation rho/sigma_r^3 propto r^-alpha, which holds for simulated dark-matter haloes over their whole resolved radial range. Considering…

Astrophysics · Physics 2009-11-13 Walter Dehnen , Dean McLaughlin

$N$-body simulations have unveiled several apparently universal properties of dark matter halos, including a cusped density profile, a power-law pseudo phase-space density $\rho/\sigma_r^3$, and a linear $\beta-\gamma$ relation between the…

Astrophysics · Physics 2011-02-11 Emmanuel Van Hese , Maarten Baes , Herwig Dejonghe

[abridged] In the dark matter (DM) halos embedding galaxies and galaxy systems the `entropy' K = \sigma^2 / \rho^{2/3} (a quantity that combines the radial velocity dispersion \sigma with the density \rho) is found from intensive N-body…

Astrophysics · Physics 2011-02-11 A. Lapi , A. Cavaliere

It has been known for nearly 20 years that the pseudo phase-space density profile of equilibrium simulated dark matter halos, $\rho(r)/\sigma^3(r)$, is well described by a power law over 3 decades in radius, even though both the density…

Cosmology and Nongalactic Astrophysics · Physics 2020-04-16 Arpit Arora , Liliya L. R. Williams

We discuss the gamma-ray signal to be expected from dark matter (DM)annihilations at the Galactic Center. To describe the DM distribution in the Galactic halo we base on the Jeans equation for self-gravitating, anisotropic equilibria. In…

High Energy Astrophysical Phenomena · Physics 2015-05-14 A. Lapi , A. Paggi , A. Cavaliere , A. Lionetto , A. Morselli , V. Vitale

We carry out fully 3-dimensional simulations of evolution from self-similar, spherically symmetric linear perturbations of a Cold Dark Matter dominated Einstein-de Sitter universe. As a result of the radial orbit instability, the haloes…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 Mark Vogelsberger , Roya Mohayaee , Simon D. M. White

We investigate the mass profile of LambdaCDM halos using a suite of numerical simulations spanning five decades in halo mass, from dwarf galaxies to rich galaxy clusters. Our analysis confirms the proposal of Navarro, Frenk & White (NFW)…

The latest cosmological N-body simulations find two intriguing properties for dark matter haloes: (1) their radial density profile, rho, is better fit by a form that flattens to a constant at the halo center (the Einasto profile) than the…

Cosmology and Nongalactic Astrophysics · Physics 2009-07-21 Chung-Pei Ma , Philip Chang , Jun Zhang

We investigate the connection between collisionless equilibria and the phase-space relation between density $\rho$ and velocity dispersion $\sigma$ found in simulations of dark matter halo formation, $F=\psd \propto r^{-\alpha}$.…

Astrophysics · Physics 2009-11-13 Eric I. Barnes , Liliya L. R. Williams , Arif Babul , Julianne J. Dalcanton

N-body simulations of dark matter halos show that the density is cusped near the center of the halo. The density profile behaves as $r^{-\gamma}$ in the inner parts, where $\gamma \simeq 1$ for the NFW model and $\gamma \simeq 1.5$ for the…

Astrophysics · Physics 2009-06-23 Ding Ma , Ping He
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