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We construct numerical models of mildly triaxial elliptical galaxies with central density cusps. Using a technique we call ``adiabatic squeezing'', we begin with a spherical gamma=1 Hernquist model and apply a drag to the velocities of the…

Popular models for describing the luminosity-density profiles of dynamically hot stellar systems (e.g., Jaffe, Hernquist, Dehnen) were constructed with the desire to match the deprojected form of an R^{1/4} light-profile. Real galaxies,…

Astrophysics · Physics 2012-04-26 Balsa Terzic , Alister W. Graham

We describe a family of circular, and elliptical, finite disks with a disk potential that is a power of the radius. These are all flattened ellipsoids, obtained by squashing finite spheres with a power-law density distribution, and cutoff…

Astrophysics · Physics 2009-10-22 R. Brada , M. Milgrom

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

We measure the ellipticity of isolated clusters of galaxies in the Sloan Digital Sky Survey (SDSS) using gravitational lensing. We stack the clusters, rotating so that the major axes of the ellipses determined by the positions of cluster…

Astrophysics · Physics 2011-02-11 Anna Kathinka Dalland Evans , Sarah Bridle

Previously, we showed that surface density profiles of the form of a power-law times a Sersic function satisfy the hydrostatic Jeans equations, a variety of observational constraints, and the condition of a minimal radial entropy profile in…

Astrophysics of Galaxies · Physics 2019-09-27 Curtis Struck , Bruce G. Elmegreen

We have selected 42 elliptical galaxies from the literature and estimated their velocity dispersions at the effective radius ($\sigma_{\re}$) and at 0.54 effective radii ($\vff$). We find by a dynamical analysis that the normalized velocity…

Astrophysics · Physics 2009-10-31 Yu-Chung N. Cheng , Lawrence M. Krauss

An iterative approach is used to construct spherically symmetric equilibrium models with an anisotropic velocity distribution. The potentialities of the method have been tested on models with known distribution functions, the…

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

Considering galaxies as self - gravitating systems of many collisionless particles allows to use methods of statistical mechanics inferring the distribution function of these stellar systems. Actually, the long range nature of the…

Cosmology and Nongalactic Astrophysics · Physics 2014-02-04 V. F. Cardone , M. P. Leubner , A. Del Popolo

We use a set of cosmological N-body simulations to investigate the structural shape of galaxy-sized cold dark matter (CDM) halos. Unlike most previous work on the subject - which dealt with shapes as measured by the inertia tensor - we…

Astrophysics · Physics 2008-11-26 E. Hayashi , J. F. Navarro , V. Springel

The anomalous rotation curves of galaxies provide compelling evidence for dark matter, yet its fundamental nature and distribution remain key unresolved issues in astrophysics. In this work, we investigate a dark matter model derived from…

General Relativity and Quantum Cosmology · Physics 2025-09-17 Jan Kuncewicz

Dynamical properties of two-component galaxy models whose stellar density distribution is described by a gamma-model while the total density distribution has a pure r^(-2) profile, are presented. The orbital structure of the stellar…

Astrophysics · Physics 2009-11-13 Luca Ciotti , Lucia Morganti , Tim de Zeeuw

Recently, two-component spherical galaxy models have been presented, where the stellar profile is described by a Jaffe law, and the total density by another Jaffe law, or by an $r^{-3}$ law at large radii. We extend these two families to…

Astrophysics of Galaxies · Physics 2020-11-04 L. Ciotti , A. Mancino , S. Pellegrini , A. Ziaee Lorzad

The statistical properties of the ellipticities of galaxy images depend on how galaxies form and evolve, and therefore constrain models of galaxy morphology, which are key to the removal of the intrinsic alignment contamination of…

Cosmology and Nongalactic Astrophysics · Physics 2013-05-28 B. Joachimi , E. Semboloni , P. E. Bett , J. Hartlap , S. Hilbert , H. Hoekstra , P. Schneider , T. Schrabback

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

Recent studies have shown that massive elliptical galaxies have total mass density profiles within an effective radius that can be approximated as \rho_{tot}\propto r^{-\gamma'}, with mean slope <\gamma'>=2.08 \pm 0.03 and scatter…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 Aaron A. Dutton , Tommaso Treu

In this series of papers we develop a formalism for constraining mass profiles in strong gravitational lenses with extended images, using fluxes in addition to positional information. We start in this paper with a circular power-law profile…

Astrophysics of Galaxies · Physics 2019-06-26 Conor M. O'Riordan , Stephen J. Warren , Daniel J. Mortlock

I propose a modification of the spherical infall model for the evolution of density fluctuations with initially Gaussian probability distribution and scale-free power spectra. I introduce a generalized form of the initial density…

Astrophysics · Physics 2007-05-23 Ewa L. Lokas

We construct stable axially symmetric models of elliptical galaxies. The particle density on phase space for these models depends monotonically on the particle energy and on the third component of the angular momentum. They are obtained as…

Astrophysics · Physics 2009-11-07 Yan Guo , Gerhard Rein

For the spherical symmetric case, all quantities describing the relaxed dark matter halo can be expressed as functions of the gravitational potential $\Phi$. Decomposing the radial velocity dispersion $\sigma_r$ with respect to $\Phi$ at…

Astrophysics · Physics 2009-11-07 J. P. Muecket , M. Hoeft