Related papers: Mapping the Galactic centre's dark cluster via Res…
We propose a scenario in which massive stars form in a self-gravitating gaseous disc around a supermassive black hole. We find that once the surface density of the disc exceeds a critical value, the disc fragments into dense clumps. The…
We have embarked in an HST program to determine the masses of black holes in spiral galaxies directly by measuring the line emission arising from an extended accretion disk. For each of the galaxies in our sample we have measured the…
Dense star clusters are spectacular self-gravitating stellar systems in our Galaxy and across the Universe - in many respects. They populate disks and spheroids of galaxies as well as almost every galactic center. In massive elliptical…
With 10 years of high-resolution imaging data now available on the stellar cluster in the Galactic Center, we analyze the dynamics of the stars at projected distances $\leq1.2''$ from the central black hole candidate Sagittarius A* (Sgr…
We present a new analytical solution to the steady-state distribution of stars close to a central supermassive black hole of mass $M_{\bullet}$ in the center of a galaxy. Assuming a continuous mass function of the form $dN/dm \propto…
The Galactic centre Nuclear Star Cluster is one of the densest stellar clusters in the Galaxy. The stars in its inner portions orbit the supermassive black hole associated with compact radio source Sgr~A* at the orbital speeds of several…
Analysing the weak lensing distortions of the images of faint background galaxies provides a means to constrain the average mass distribution of cluster galaxies and potentially to test the extent of their dark matter haloes as a function…
Direct numerical integrations of the Fokker-Planck equation in energy-angular momentum space are carried out for stars orbiting a supermassive black hole (SBH) at the center of a galaxy. The algorithm, which was described in detail in an…
The Galactic center provides a unique astrophysical laboratory for us to study various astrophysical processes. In this paper, we review and outline the latest results from observations of Sgr~A$^*$ in terms of source structure and…
This paper is the third in a series presenting the results of direct numerical integrations of the Fokker-Planck equation for stars orbiting a supermassive black hole (SBH) at the center of a galaxy. The algorithm of Paper II included…
There is a supermassive black hole, a gaseous accretion disk and compact star cluster in the center of active galactic nuclei, as known today. So the activity of AGN can be represented as the result of interaction of these three subsystems.…
The supermassive black holes found at the centers of galaxies are often surrounded by dense star clusters. The ages of these clusters are generally longer than the resonant-relaxation time and shorter than the two-body relaxation time over…
This is a pedagogical review of recent results on the interactions of central massive black holes with stars very near them, focused on the black hole in the center of the Milky Way. Table of contents: [1] Introduction [2] Stellar dynamics…
The Galactic Center is an excellent laboratory for studying phenomena and physical processes that may be occurring in many other galactic nuclei. The Center of our Milky Way is by far the closest galactic nucleus, and observations with…
Aims. In this paper we continue our study of density cusps that may contain central black holes. Methods. We recall our attempts to use distribution functions with a memory of self-similar relaxation, but mostly they apply only in…
Supermassive black holes inhabit galactic nuclei, and their presence influences in crucial ways the evolution of the stellar distribution. The low-density cores observed in bright galaxies are probably a result of black hole infall, while…
New measurements of the stellar-mass deficits at the centers of luminous elliptical galaxies are presented. These were derived considering the following observational facts. Firstly, ``core'' galaxies, which are thought to have had their…
We analyze three sets of infrared star counts in the inner ~0.5 pc of the Galactic Center. We perform statistical tests on the star counts and model in detail the extinction field and the effects of dwarf-giant collisions on the luminosity…
We study the dynamics of nuclear star clusters, the dense stellar environments surrounding massive black holes in the centers of galaxies. We consider angular momentum diffusion due to two-body scatterings among stellar objects and energy…
We use semi-analytic modeling on top of the Millennium simulation to study the joint formation of galaxies and their embedded supermassive black holes. Our goal is to test scenarios in which black hole accretion and quasar activity are…