English
Related papers

Related papers: Scale-free dynamical models for galaxies: flattene…

200 papers

We develop a flexible set of action-based distribution functions (DFs) for stellar haloes. The DFs have five free parameters, controlling the inner and outer density slope, break radius, flattening and anisotropy respectively. The DFs…

Astrophysics of Galaxies · Physics 2015-09-30 A. A. Williams , N. W. Evans

We present a family of self-consistent axisymmetric stellar systems that have analytic distribution functions (DFs) of the form f(J), so they depend on three integrals of motion and have triaxial velocity ellipsoids. The models, which are…

Astrophysics of Galaxies · Physics 2015-06-18 James Binney

Dwarf spheroidal galaxies (dSphs) are prime laboratories for studying dark matter (DM) and the black hole demographics in the low-mass regime. These systems are also often flattened; nevertheless most studies rely on spherical models,…

Astrophysics of Galaxies · Physics 2026-04-29 R. Pascale , G. Battaglia , J. M. Arroyo-Polonio , E. Vasiliev , C. Nipoti , G. F. Thomas

We present a family of spherical models for elliptical galaxies and bulges consisting of a stellar component and a central black hole. All models in this family share the same stellar density profile, which has a steep central cusp. The…

Astrophysics · Physics 2009-11-10 Maarten Baes , Herwig Dejonghe

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 construct axisymmetric mass models for dwarf spheroidal (dSph) galaxies in the Milky Way to obtain plausible limits on the non-spherical structure of their dark halos. This is motivated by the fact that the observed luminous parts of the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 Kohei Hayashi , Masashi Chiba

We study the dynamical properties of spherical galaxies with surface luminosity profile described by the R^{1/m}-law, in which a variable degree of orbital anisotropy is allowed. The parameter m for the present models covers the range…

Astrophysics · Physics 2007-05-23 L. Ciotti , B. Lanzoni

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

The Jeans equations give the second moments or stresses required to support a stellar population against the gravity field. A general solution of the Jeans equations for arbitrary axisymmetric scale-free densities in flattened scale-free…

Astrophysics · Physics 2015-06-24 N. W. Evans , R. M. Häfner , P. T. de Zeeuw

The dynamical properties of spherically symmetric galaxy models, where a Jaffe (1983) stellar density profile is embedded in a total mass density decreasing as $r^{-3}$ at large radii, are presented. The orbital structure of the stellar…

Astrophysics of Galaxies · Physics 2019-10-02 L. Ciotti , A. Mancino , S. Pellegrini

We use dynamical models that include bulk rotation, velocity dispersion anisotropy and both stars and dark matter to explore the conditions that give rise to the early-type galaxy scaling relations referred to as the Fundamental Plane (FP)…

Astrophysics of Galaxies · Physics 2015-11-18 Huanian Zhang , Dennis Zaritsky

The contour integral method of Hunter & Qian is applied to axisymmetric galaxy models in which the distribution function (DF) is of the form f=f(E,L_z), where E and L_z are the classical integrals of motion in an axisymmetric potential. A…

Astrophysics · Physics 2015-06-24 E. E. Qian , P. T. de Zeeuw , R. P. van der Marel , C. Hunter

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

This paper introduces a new two-parameter family of dwarf spheroidal (dSph) galaxy models. The density distribution has a Plummer profile and falls like the inverse fourth power of distance in projection, in agreement with the star-count…

Astrophysics · Physics 2009-11-07 M. I. Wilkinson , J. Kleyna , N. W. Evans , G. Gilmore

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

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

The analytical phase-space distribution function (DF) of spherical self--consistent galaxy (or cluster) models, embedded in a dark matter halo, where both density distributions follow the Hernquist profile, with different total masses and…

Astrophysics · Physics 2009-10-28 Luca Ciotti

We study the distribution of dark matter in dwarf spheroidal galaxies by modelling the moments of their line-of-sight velocity distributions. We discuss different dark matter density profiles, both cuspy and possessing flat density cores.…

Astrophysics · Physics 2009-11-07 Ewa L. Lokas

We present self-consistent triaxial stellar systems that have analytic distribution functions (DFs) expressed in terms of the actions. These provide triaxial density profiles with cores or cusps at the centre. They are the first…

Astrophysics of Galaxies · Physics 2015-09-30 Jason L. Sanders , N. Wyn Evans

It is well known that the density and anisotropy profile in the inner regions of a stellar system with positive phase-space distribution function are not fully independent. Here we study the interplay between density profile and orbital…

Astrophysics · Physics 2009-11-13 Luca Ciotti , Lucia Morganti
‹ Prev 1 2 3 10 Next ›