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Related papers: Anisotropic Models of Dark Halos

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We compare the DARKexp differential energy distribution, N(E) \propto \exp(\phi_0-E)-1, obtained from statistical mechanical considerations, to the results of N-body simulations of dark matter halos. We first demonstrate that if DARKexp…

Cosmology and Nongalactic Astrophysics · Physics 2010-12-14 Liliya L. R. Williams , Jens Hjorth , Radoslaw Wojtak

Context: The Einasto model has become one of the most popular models for describing the density profile of dark matter haloes. There have been relatively few comprehensive studies on the dynamical structure of the Einasto model, mainly…

Astrophysics of Galaxies · Physics 2022-11-09 Maarten Baes

Context. We have investigated the structure and kinematics of triaxial final models formed due to radial-orbit instability from a set of equilibrium anisotropic spherical systems of the Osipkov-Merritt type. Aims. We show that the…

Astrophysics · Physics 2008-11-18 Piffl T. , Sotnikova N. Ya

Various analytic expressions have been proposed for the density profile of dark matter halos. We consider six of these expressions for which the density profile has a power-law fall-off rho proportional to r^{-3} at large radii and a…

Astrophysics · Physics 2007-05-23 Lawrence M. Widrow

Using cosmological N-body simulations we study the line-of-sight velocity distribution of dark matter haloes focusing on the lowest-order even moments, dispersion and kurtosis, and their application to estimate the mass profiles of…

Astrophysics · Physics 2009-11-13 Radoslaw Wojtak , Ewa L. Lokas , Stefan Gottloeber , Gary A. Mamon

The non-linear cosmic web environment of dark matter haloes plays a major role in shaping their growth and evolution, and potentially also affects the galaxies that reside in them. We develop an analytical (halo model) formalism to describe…

Cosmology and Nongalactic Astrophysics · Physics 2021-02-24 Aseem Paranjape

The velocity anisotropy of particles inside dark matter (DM) haloes is an important physical quantity, which is required for the accurate modelling of mass profiles of galaxies and clusters of galaxies. It is typically measured using the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 Radoslaw Wojtak , Stefan Gottloeber , Anatoly Klypin

An analytic galaxy model with $\rho \sim r^{-1}$ at small radii and $\rho \sim r^{-3.5}$ at large radii is presented. The asymptotic density fall-off is slower than the Hernquist model, but faster than the Navarro-Frenk-White (NFW) profile…

Astrophysics of Galaxies · Physics 2018-02-21 E. Lilley , N. W. Evans , J. L. Sanders

We have performed a series of high resolution N-body experiments on a Connection Machine CM-5 in order to study the stability of collisionless self-gravitating spherical systems. We interpret our results in the framework of symplectic…

Astrophysics · Physics 2015-06-24 J. Perez , J-M Alimi , J-J Aly , H. Scholl

Using the standard dynamical theory of spherical systems, we calculate the properties of spherical galaxies and clusters whose density profiles obey the universal form first obtained in high resolution cosmological N-body simulations by…

Astrophysics · Physics 2009-10-31 Ewa L. Lokas , Gary A. Mamon

We performe N-body simulations of encounters between spherical systems surrounded by a spherical halo. Following a preceding paper with a similar aim, the initial systems include a spherical Jaffe model for the luminous matter and a…

Astrophysics · Physics 2011-08-23 A. C. Gonzalez-Garcia , T. S. van Albada

We present new analytical distribution functions for anisotropic spherical galaxies. They have the density profiles of the gamma-models, which allow a wide range of central density slopes, and are widely used to fit elliptical galaxies and…

Astrophysics · Physics 2008-11-26 Pieter Buyle , Chris Hunter , Herwig Dejonghe

In the framework of nonextensive statistical mechanics, the equilibrium structures of astrophysical self-gravitating systems are stellar polytropes, parameterized by the polytropic index n. By careful comparison to the structures of…

Astrophysics · Physics 2009-06-23 Chloé Féron , Jens Hjorth

We construct conformastat spherically symmetric spacetimes representing anisotropic fluid matter distributions from given solutions of the Poisson's equation of Newtonian gravity and its corresponding circular speed profile. As simple…

General Relativity and Quantum Cosmology · Physics 2022-03-21 Gonzalo García-Reyes

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

Motivated by the recent detection of an enhanced clustering signal along the major axis of haloes in N-body simulations, we derive a formula for the anisotropic density distribution around haloes and voids on large scales. Our model, which…

Cosmology and Nongalactic Astrophysics · Physics 2012-12-14 Péter Pápai , Ravi K. Sheth

$N$-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

In the context of the study of the properties of the mutual mass distribution of the bright and dark matter in elliptical galaxies, present a family of two-component, spherical, self-consistent galaxy models, where one density distribution…

Astrophysics · Physics 2009-10-31 L. Ciotti

We present a new method to construct fully self-consistent equilibrium models of multi-component disc galaxies similar to the Milky Way. We define distribution functions for the stellar disc and dark halo that depend on phase space position…

Astrophysics of Galaxies · Physics 2015-07-03 T. Piffl , Z. Penoyre , J. Binney

We extend the random-walk model of Vitvitska et al. for predicting the spins of dark matter halos from their merger histories. Using updated merger rates, orbital parameter distributions, and N-body constraints we show that this model can…

Astrophysics of Galaxies · Physics 2020-07-08 Andrew Benson , Christoph Behrens , Yu Lu