Related papers: The Dense Stellar Systems Around Galactic Massive …
Various past theoretical considerations and observational efforts suggest the presence of a population of stellar-mass black holes in the innermost parsec of the Galactic centre. In this Letter, we investigate the impact of these black…
Globular clusters (GCs) constitute a system which is evolving because of various interactions with the galactic environment. Evolution may be the explanation of many observed features of Globular Cluster Systems (GCSs); the different radial…
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…
High spatial resolution, near-infrared imaging and spectroscopy of the nuclear star cluster have given key new insights about the dynamics, evolution and mass distribution in the Milky Way Center. The central parsec is powered by a cluster…
A large fraction of bulgeless disk galaxies contain young compact stellar systems at their centers, in spite of the local gravitational stability of these disks. We evaluate two contrasting hypotheses for the origin of the nuclear star…
Centers of galaxies host both a supermassive black hole and a dense stellar cluster. Such an environment should lead to stellar collisions, possibly at very high velocities so that the total energy involved is of the same order as…
Supermassive black holes have been discovered at the centers of galaxies, and also in globular clusters. The data shows correlations between the black hole mass and the elliptical galaxy mass or globular cluster mass. It is shown that this…
Different types of observations, together with consistent and physical modelizations, suggest as realistic the hypothesis of enrichement of galactic nuclei by mean of massive globular clusters orbitally decayed and merged in the inner…
As self-gravitating systems, dense star clusters exhibit a natural diffusion of energy from their innermost to outermost regions, which leads to a slow and steady contraction of the core until it ultimately collapses under gravity. However,…
We explore here an scenario for massive black hole formation driven by stellar collisions in galactic nuclei, proposing a new formation regime of global instability in nuclear stellar clusters triggered by runaway stellar collisions. Using…
Supermassive black holes are found in most galactic nuclei. A large fraction of these nuclei also contain a nuclear stellar cluster surrounding the black hole. Here we consider the idea that the nuclear stellar cluster formed first and that…
Black holes and neutron stars present extreme forms of matter that cannot be created as such in a laboratory on Earth. Instead, we have to observe and analyze the experiments that are ongoing in the Universe. The most telling observations…
We present preliminary results of the application of a new sophisticated code which allows high precision integration of orbits of stars belonging to a dense stellar system moving in the vicinity of a massive black hole. This mimics the…
Galactic nuclei host central massive objects either in the form of supermassive black holes or nuclear stellar clusters. Recent investigations have shown that both components co-exist in at least a few galaxies. In this paper we explore the…
In this review, I present the case for how massive stars may form through stellar collisions. This mechanism requires very high stellar densities, up to 4 orders of magnitude higher than are observed in the cores of dense young clusters. In…
The centers of most galaxies in the local universe are occupied by compact, barely resolved sources. Based on their structural properties, position in the fundamental plane, and integrated spectra, these sources clearly have a stellar…
We point out that a high number density of stars in the core of a dense star cluster such as the central stellar cluster at the Galactic center, where many stars possess strong stellar winds, should result in collisions of those winds. The…
Most clusters and groups of galaxies contain a giant elliptical galaxy in their centres which far outshines and outweighs normal ellipticals. The origin of these brightest cluster galaxies is intimately related to the collapse and formation…
The centers of galaxies host a supermassive black hole surrounded by a dense stellar cluster. The cluster is expected to develop mass segregation, in which gravitational scatterings among the stars cause heavier objects to sink closer to…
Rapid formation of supermassive black holes occurs in dense nuclear star clusters that are initially gas-dominated. Stellar-mass black hole remnants of the most massive cluster sink into the core, where a massive runaway black hole forms as…