Related papers: Modelling elliptical galaxies: phase-space constra…
The two properties of the radial mass distribution of a gravitational lens that are well-constrained by Einstein rings are the Einstein radius R_E and xi2 = R_E alpha''(R_E)/(1-kappa_E), where alpha''(R_E) and kappa_E are the second…
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…
Spherical systems with polytropic equations of state are of great interest in astrophysics. They are widely used to describe neutron stars, red giants, white dwarfs, brown dwarfs, main sequence stars, galactic halos, and globular clusters…
Early - type galaxies (ETGs) define a narrow strip in the size - mass plane because of the observed correlation between the effective radius $R_{eff}$ and the total stellar mass $M_{\star}$. When expressed in logarithmic units, a linear…
We analyze a sample of 23 supermassive elliptical galaxies (central velocity dispersion larger than 330 km s-1), drawn from the SDSS. For each object, we estimate the dynamical mass from the light profile and central velocity dispersion,…
We develop the theory of anomalous elasticity in two-dimensional flexible materials with orthorhombic crystal symmetry. Remarkably, in the universal region, where characteristic length scales are larger than the rather small Ginzburg scale…
We present a new two dimensional model for elliptic (i.e., shape anisotropic) patchy colloids, where the impenetrable core of the particles is decorated on its co-)vertices by Kern-Frenkel type of patches. Using (i) well-documented criteria…
Early-type galaxies exhibit thermal and molecular resonance emission from dust that is shed and heated through stellar mass loss as a subset of the population moves through the AGB phase of evolution. Because this emission can give direct…
We investigate the globular cluster system of the isolated elliptical NGC 7796, present new photometry of the galaxy, and use published kinematical data to constrain the dark matter content. Deep images in B and R, obtained with the VIsible…
We present a method for fitting orbit-superposition models to the kinematics of discrete stellar systems when the available stellar sample has been filtered by a known selection function. The fitting method can be applied to any model in…
Starting from the central density slope-anisotropy theorem of An and Evans (2006), recent investigations have shown that the involved density slope-anisotropy inequality holds not only at the center, but at all radii (i.e. globally) in a…
Traditionally, the mass / velocity anisotropy degeneracy (MAD) inherent in the spherical, stationary, non-streaming Jeans equation has been handled by assuming a mass profile and fitting models to the observed kinematical data. Here, the…
We present an analytic formulation for the equilibrium gas density profile of early-type galaxies that explicitly includes the contribution of stars in the gravitational potential. We build a realistic model for an isolated elliptical…
We study the mass, velocity dispersion, and anisotropy profiles of $\Lambda$CDM halos using a suite of N-body simulations of unprecedented numerical resolution (the {\it Aquarius Project}). Our analysis confirms a number of results claimed…
We use three--integral models to infer the distribution function (DF) of the boxy E3-E4 galaxy NGC 1600 from surface brightness and line profile data on the minor and major axes. We assume axisymmetry and that the mass-to-light ratio is…
We estimate the masses of elliptical galaxies out to five effective radii using planetary nebulae and globular clusters as tracers. A sample of 15 elliptical galaxies with a broad variation in mass is compiled from the literature. A…
The spectral hardenings of cosmic ray nuclei above $\sim 200$ GV followed by softenings around 10 TV, the knee of the all-particle spectrum around PeV energies, as well as the pattern change of the amplitude and phase of the large-scale…
We study the stability of a family of spherical equilibrium models of self-gravitating systems, the so-called $\gamma-$models with Osipkov-Merritt velocity anisotropy, by means of $N-$body simulations. In particular, we analyze the effect…
Spherically symmetric equilibrium configurations of perfect fluid obeying a polytropic equation of state are studied in spacetimes with a repulsive cosmological constant. The configurations are specified in terms of three parameters---the…
In this paper, we develop a new relativistic compact stellar model for a spherically symmetric anisotropic matter distribution. The model has been obtained through generating a new class of solutions by invoking the Tolman {\em ansatz} for…