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Related papers: Anisotropic Models of Dark Halos

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Anisotropies in the electromagnetic emission produced by dark matter annihilation or decay in the extragalactic sky are a recent tool in the quest for a particle dark matter evidence. We review the formalism to compute the two-point angular…

Cosmology and Nongalactic Astrophysics · Physics 2014-01-28 Nicolao Fornengo , Marco Regis

Galaxies and the dark matter halos that host them are not spherically symmetric, yet spherical symmetry is a helpful simplifying approximation for idealised calculations and analysis of observational data. The assumption leads to an exact…

Astrophysics of Galaxies · Physics 2016-01-29 Andrew Pontzen , Justin Read , Romain Teyssier , Fabio Governato , Alessia Gualandris , Nina Roth , Julien Devriendt

Navarro, Frenk, and White have suggested that the density profiles of simulated dark matter halos have a ``universal'' shape so that a given halo can be characterized by a single free parameter which fixes its mass. In this paper, we…

Astrophysics · Physics 2009-10-30 Richard N. Henriksen , Lawrence M. Widrow

We present a proposal for the full phase space distribution of the Milky Way halo. The model is axially and reflection symmetric and its time evolution is self-similar. It describes the halo as a set of discrete dark matter flows with…

Astrophysics · Physics 2009-02-20 L. D. Duffy , P. Sikivie

We consider the reasons why a cuspy NFW-like profile persistently occurs in N-body simulations, in contradiction to some astronomical observations. The routine method of testing the convergence of N-body simulations (in particular, the…

Cosmology and Nongalactic Astrophysics · Physics 2014-10-03 Anton N. Baushev

Resolved rotation curves (RCs) are our best probe of the dark matter distribution around individual galaxies. However their acquisition is resource-intensive, rendering them impractical for large-scale surveys and studies at higher…

Astrophysics of Galaxies · Physics 2024-09-02 Tariq Yasin , Harry Desmond

We present a class of exact solutions of Einstein's gravitational field equations describing spherically symmetric and static anisotropic stellar type configurations. The solutions are obtained by assuming a particular form of the…

General Relativity and Quantum Cosmology · Physics 2017-10-04 T. Harko , M. K. Mak

We present a new method for constructing equilibrium phase models for stellar systems, which we call the iterative method. It relies on constrained, or guided evolution, so that the equilibrium solution has a number of desired parameters…

Astrophysics · Physics 2009-11-13 S. A. Rodionov , E. Athanassoula , N. Ya Sotnikova

Cosmological N--body simulations have revealed a remarkable similarity in the structure of dark matter halos formed in hierarchically clustering universes. Regardless of halo mass, cosmological parameters, and power spectrum of initial…

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

We have developed a spherically symmetric dynamical model of a dwarf spheroidal galaxy using the Schwarzschild method. This type of modelling yields constraints both on the total mass distribution (e.g. enclosed mass and scale radius) as…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 Maarten A. Breddels , Amina Helmi , R. C. E. van den Bosch , G. van de Ven , G. Battaglia

Using the model for (bottom-up) hierarchical halo growth recently developed by Salvador-Sol\'e et al. (2012), we derive the typical spherically averaged density profile for haloes with several relevant masses in the concordant warm dark…

Cosmology and Nongalactic Astrophysics · Physics 2012-07-10 Jordi Viñas , Eduard Salvador-Solé , Alberto Manrique

Spherical galaxy models with radially anisotropic velocity distributions merge faster than their isotropic counterparts. Here we investigate the effects of radially anisotropic haloes on the dynamics of disc galaxy encounters. We use stable…

Astrophysics of Galaxies · Physics 2025-08-26 Tatum M. Umiamaka , Joshua E. Barnes

Using cosmological N-body simulations we study the radial velocity distribution in dark matter haloes focusing on the lowest-order even moments, dispersion and kurtosis. We determine the properties of ten massive haloes in the simulation…

Astrophysics · Physics 2009-11-10 Radoslaw Wojtak , Ewa L. Lokas , Stefan Gottloeber , Gary A. Mamon

Galaxy models comprising several components (including dark matter) that are bound by the self-consistently generated gravitational field are readily constructed from distribution functions (DFs) that are analytic functions of the action…

Astrophysics of Galaxies · Physics 2026-05-20 James Binney

We review and develop a new class of "dark energy" models, in which the relativistic theory of solids is used to construct material models of dark energy. These are models which include the effects of a continuous medium with well defined…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-19 Jonathan A. Pearson

Shape estimates that quantify the halo anisotropic mass distribution are valuable parameters that provide information on their assembly process and evolution. Measurements of the mean shapes for a sample of cluster-sized halos can be used…

N-body simulations of collisionless collapse have offered important clues to the construction of realistic stellar dynamical models of elliptical galaxies. Such simulations confirm and quantify the qualitative expectation that rapid…

Astrophysics · Physics 2009-11-10 G. Bertin , M. Trenti

We develop a new model for a spherically symmetric dark matter fluid sphere containing two regions: {\bf (i)} Isotropic inner region with constant density and {\bf (ii)} Anisotropic outer region. We solve the system of field equation by…

General Relativity and Quantum Cosmology · Physics 2020-12-02 Shyam Das , Nayan Sarkar , Monimala Mondal , Farook Rahaman

Understanding the nature of dark matter is among the top priorities of modern physics. However, due to its inertness, detecting and studying it directly in terrestrial experiments is extremely challenging. Numerical N-body simulations…

Astrophysics of Galaxies · Physics 2024-03-06 Zhen Li , Steen H. Hansen

We Consider a cosmological model based on a generalization of the equation of state proposed by Nojiri and Odintsov [46] and \v{S}tefan\v{c}i'c [47], [48]. We argue that this model works as a dark fluid model which can interpolate between…

General Relativity and Quantum Cosmology · Physics 2023-02-17 Esraa Elkhateeb