Related papers: Two-component Jaffe models with a central black ho…
We investigate the circumstances which allow a black hole to remain put at the galactic centre when the stellar core is anisotropic. We use N-body calculations to study the response of stellar orbit families embedded in a larger, isotropic…
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…
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…
In many investigations involving accretion on a central point mass, ranging from observational studies to cosmological simulations, including semi-analytical modelling, the classical Bondi accretion theory is the standard tool widely…
$N$-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…
We first stress that any spherically symmetric galactic model whose integrated mass profile $M (r) \to 0$ as $r \to 0$ is physically consistent close to the centre only provided that the circular velocity $v_c (r) \to 0$ and the…
We present here a self-consistent, tridimensional model of a disc galaxy composed by a number of ellipsoidal distributions of matter having different flattening and density profile. The model is self-consistent and takes into account the…
We present a determination of the mass of the supermassive black hole (BH) and the nuclear stellar orbital distribution of the elliptical galaxy Centaurus A (NGC5128) using high-resolution integral-field observations of the stellar…
We consider the problem of determining the structure of the dark halo of nearby dwarf spheroidal galaxies (dSphs) from the spherical Jeans equations. Whether the dark halos are cusped or cored at the centre is an important strategic problem…
(Abridged) We present mass models of a sample of 14 spiral and 14 S0 galaxies that constrain their stellar and dark matter content. For each galaxy we derive the stellar mass distribution from near-infrared photometry under the assumptions…
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…
We reinvestigate the effect of annihilations on the distribution of collisionless dark matter (DM) in a spherical density spike around a massive black hole. We first construct a very simple, pedagogic, analytic model for an isotropic phase…
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…
We study velocity moments of elliptical galaxies in the Coma cluster using Jeans equations. The dark matter distribution in the cluster is modelled by a generalised formula based upon the results of cosmological N-body simulations. Its…
We study the mass distribution in six nearby (z<0.06) relaxed Abell clusters of galaxies A0262, A0496, A1060, A2199, A3158 and A3558. Given the dominance of dark matter in galaxy clusters we approximate their total density distribution by…
We discuss the kinematical structure of a two-parameter family of isotropic models with a central black hole. The family contains the slope of the central density cusp and the relative black hole mass as parameters. Most of the basic…
We investigate spherically symmetric classes of anisotropic solutions within the realm of a schematic gravitational decoupling scheme, primarily decoupling through minimal geometric deformation, applied to non-rotating, ultra-compact,…
This paper presents two families of phase-space distribution functions (DFs) that generate scale-free spheroidal mass densities in scale-free spherical potentials. The `case I' DFs are anisotropic generalizations of the flattened f(E,L_z)…
A set of infinitesimal ${\rm Virasoro_{\,L}}\otimes{\rm Virasoro_{\,R}}$ diffeomorphisms are presented which act non-trivially on the horizon of a generic Kerr black hole with spin J. The covariant phase space formalism provides a formula…
The stellar halo of the Milky Way is known to have a highly lumpy structure due to the presence of tidal debris and streams accreted from the satellite galaxies. The abundance and distribution of these substructures can provide a wealth of…