The capture rates of stars onto supermassive black holes depend strongly on the spatial and kinematical distribution of the stars at the centre of bulges and elliptical galaxies. We here explore the possibility that all ellipticals/bulges have initially isothermal cusps (ρ ∝ r). If the orbits can be adequately randomized a significant fraction of the total mass of black holes in the bulges of g...

A drop of semicrystalline polymer, poly(ethylene oxide) (PEO), solution was placed in a restricted geometry consisting of a sphere on a flat substrate (i.e., sphere-on-flat geometry). Upon solvent evaporation from the sphere-on-flat geometry, microscopic concentric rings of PEO with appropriate high molecular weight were produced via controlled, repetitive pinning ("stick") and depinning ("slip...

We present results of a weak gravitational lensing survey of six X-ray selected high-redshift clusters of galaxies. We find that the masses of the clusters derived from weak lensing are comparable to those derived from the X-ray observations. We show that many of the clusters have significant substructure not observed in the X-ray observations and that for the more massive clusters a singular i...

Abstract. We investigate the finite source size effect in the context of the wave optics in the gravitational lensing. The magnification of an extended source is presented in an analytic manner for the singular isothermal sphere lens model as well as the point mass lens model with the use of the thin lens approximation. The condition that the finite source size effect becomes substantial is dem...

Using the results of a high mass resolution (256 particles) N-body simulation of a cluster-forming region, we study the statistic σv− M for low mass halos (M < 1012M⊙), and we compare it with three theoretical models. At the final redshift halos are well described by the Truncated Isothermal Sphere model recently introduced by Shapiro, Iliev & Raga (1999). We speculate that this is a consequenc...

Gravity is nearly a universal constant in the cusp of an NFW galaxy halo. Inside this external field an isothermal gas sphere will collapse and trigger a starburst if above a critical central pressure. Thus formed spheroidal stellar systems have Sersic-profile and satisfy the Faber-Jackson relation. The process is consistent with observed starbursts. We also recover the MBH −σ∗ relation, if the...

This article investigates the nonlinear, steady boundary layer flow and heat transfer of an incompressible Eyring-Powell non-Newtonian fluid from an isothermal sphere with Biot number effects. The transformed conservation equations are solved numerically subject to physically appropriate boundary conditions using a second-order accurate implicit finite-difference Keller Box technique. The influ...

Many multiply{imaged quasars have been found over the years, but none so far with image separation in excess of 8 00. The absence of such large splittings has been used as a test of cosmological models: the standard Cold Dark Matter model has been excluded on the basis that it predicts far too many large{separation double images. These studies assume that the lensing structure has the mass proo...

This article deals with the gravitational lensing (GL) of gravitational waves (GW). We compute the increase in the number of detected GW events due to GL. First, we check that geometrical optics is valid for the GW frequency range on which Earth-based detectors are sensitive, and that this is also partially true for what concerns the future space-based interferometer LISA. To infer this result,...

All axisymmetric self-similar equilibria of self-gravitating, rotating, isothermal systems are identified by solving the nonlinear Poisson equation analytically. There are two families of equilibria: (1) Cylindrically symmetric solutions in which the density varies with cylindrical radius as R, with 0 ≤ α ≤ 2. (2) Axially symmetric solutions in which the density varies as f(θ)/r, where r is the...