Related papers: Integrable models of galactic discs with double nu…
Using deep near-infrared imaging of the Hubble Deep Field South with ISAAC on the Very Large Telescope we find 6 large disk-like galaxies at redshifts z = 1.4-3.0. The galaxies, selected in K_s (2.2 micron), are regular and surprisingly…
The Hubble Space Telescope WFPC2 is being used to obtain high-resolution images in the V and I bands for several thousand distant galaxies as part of the Medium Deep Survey (MDS). An important scientific aim of the MDS is to identify…
The structure of dust spirals in the nuclei of the SAab-type Liner galaxies NGC 4450 and NGC 4736 is studied using archival HST PC images. The spirals are typically only several hundredths of a magnitude fainter than the neighboring disks,…
Debris disc analysis and modelling provide crucial information about the structure and the processes at play in extrasolar planetary systems. In binary systems, this issue is more complex because the disc should in addition respond to the…
We analyze the nuclear stellar dynamics of the SB0 galaxy NGC 1023, utilizing observational data both from the Space Telescope Imaging Spectrograph aboard the Hubble Space Telescope and from the ground. The stellar kinematics measured from…
We study a new class of equilibrium two-parametric distribution functions of spherical stellar systems with radially anisotropic velocity distribution of stars. The models are less singular counterparts of the so called generalized…
Mergers can be detected as double-peak narrow emission line galaxies but they are difficult to disentangle from disc rotations and gas outflows. We aim to properly detect such galaxies and distinguish the underlying mechanisms. Relying on…
For a sample of 22 core ellipticals and 22 power law ellipticals, I examine the apparent axis ratios of isophotes as a function of the dynamical time at the isophote's mean radius. The two types of elliptical galaxy have a significantly…
I propose a scenario for the formation of double-ring systems, as observed in some planetary nebulae and in the outer rings of SN 1987A. In this scenario, two jets, one jet on each side of the equatorial plane, expand into a thin, dense…
We analyse IRAS and COBE DIRBE data at wavelengths between 2.2 and 240 mu of the central 500pc of the Galaxy and derive the large-scale distribution of stars and interstellar matter in the Nuclear Bulge. Models of the Galactic Disk and…
This is the second paper of our series of works of studying the effects of active galactic nuclei (AGN) feedback on the cosmological evolution of an isolated elliptical galaxy by performing two-dimensional high-resolution hydrodynamical…
We explore the regular or chaotic nature of orbits of stars moving in the meridional (R,z) plane of an axially symmetric time-dependent disk galaxy model with a central, spherically symmetric nucleus. In particular, mass is linearly…
We use numerical simulations to study the evolution of triaxial elliptical galaxies with central black holes. In contrast to earlier numerical studies which used galaxy models with central density ``cores,'' our galaxies have steep central…
The robustness of stellar-dynamical black hole (BH) mass measurements is illustrated using 7 galaxies that have results from independent groups. Derived masses have remained constant to a factor of about 2 as spatial resolution has improved…
Ultra compact stellar models with a two-zone uniform density equation of state are considered. They are shown to provide neat examples of optical geometries exhibiting double necks, implying that the gravitational wave potential has a…
We investigate the evolution of mass density profiles in secular disk galaxy models, paying special attention to the development of a two-component profile from a single initial exponential disk free of cosmological evolution (i.e., no…
Starting with the spherical Jeans equation, we show that there exists a radius where the mass enclosed depends only on the projected tangential velocity dispersion, assuming that the anisotropy profile slowly varies. This is…
We argue that there exists a new class of completely smooth 1/8-BPS, three-charge bound state configurations that depend upon arbitrary functions of two variables. These configurations are locally 1/2-BPS objects in that if they form an…
A considerable fraction of the massive quiescent galaxies at \emph{z} $\approx$ 2, which are known to be much more compact than galaxies of comparable mass today, appear to have a disk. How well can we measure the bulge and disk properties…
The gas dynamics in the Galactic disc is modeled by releasing an initially axisymmetric SPH component in a completely self-consistent and symmetry-free 3D N-body simulation of the Milky Way in which the stellar components display a…