Related papers: Galactic nuclear activity induced by globular clus…
Star clusters have hierarchical patterns in space and time, suggesting formation processes in the densest regions of a turbulent interstellar medium. Clusters also have hierarchical substructure when they are young, which makes them all…
The dynamics of a close binary system of globular clusters is considered. It is shown that the star transfer process from one of the components to the other should lead to the decrease of dimension of the first cluster with simultaneous…
Nuclear Star Clusters are observed at the center of many galaxies. In particular in the center of the Milky Way the Nuclear Star Cluster coexists with a cen- tral supermassive black hole. The origin of these clusters is still unknown; a…
We studied and compared the radial profiles of globular clusters and of the stellar bulge component in three galaxies of the Fornax cluster observed with the WFPC2 of the HST. A careful comparative analysis of these distributions confirms…
The origin of metal-rich, highly flattened, and rapidly rotating disk globular cluster system in the Galaxy is one of longstanding issues in the context of the Galaxy formation. Our numerical simulations suggest a new ``two-fold'' scenario…
Nuclear stellar clusters are common in the center of galaxies. We consider the possibility that their progenitors assumed to be globular clusters may have formed elsewhere, migrated to and assembled near their present location. The main…
Dynamical evolution plays a key role in shaping the current properties of star clusters and star cluster systems. A detailed understanding of the effects of evolutionary processes is essential to be able to disentangle the properties which…
The dynamics of galactic nuclei can be affected by several mechanisms. Among these are stellar evolution, stellar collisions, mass segregation, and tidal disruptions of stars due to the central black hole. In this presentation I will…
Globular clusters are collisional systems, meaning that the stars inside them interact on timescales much shorter than the age of the Universe. These frequent interactions transfer energy between stars and set up observable trends that tell…
Understanding our Galactic Center is easier with insights from nearby galactic nuclei. Both the star formation activity in nuclear gas disks, driven by bars and nuclear bars, and the fueling of low-luminosity AGN, followed by feedback of…
Globular clusters can decay to the center of their mother galaxy carrying a quantity of mass sufficient to sustain the gravitational activity of a small pre-existing nucleus and to accrete it in a significant way. The AGN luminosity and…
Nuclear Star Clusters (NSCs) are often present in spiral galaxies as well as resolved Stellar Nuclei (SNi) in elliptical galaxies centres. Ever growing observational data indicate the existence of correlations between the properties of…
We apply the idea that dense stellar systems in the central region of galaxies are formed via globular cluster mergers to the formation of the nuclear star cluster of the Milky Way, where a massive black hole is present. Our high precision…
Many, if not all, galaxies host massive compact objects at their centers. They are present as singularities (super massive black holes) or high density star clusters (nuclear tar clusters). In some cases they coexist, and interact more or…
Recent progress in studies of globular clusters has shown that they are not simple stellar populations, being rather made of multiple generations. Evidence stems both from photometry and spectroscopy. A new paradigm is then arising for the…
Globular star clusters that formed at the same cosmic time may have evolved rather differently from a dynamical point of view (because that evolution depends on the internal environment) through a variety of processes that tend…
The QCD phase transition in the early universe may provide primordial black hole nuclei for globular clusters. We consider the accretion and star formation that follow, once 1000 solar mass nuclei have formed. When such a nucleus has…
Globular clusters provide a unique probe of galaxy formation and evolution. Here I briefly summarize the known observational properties of globular cluster systems. One re-occurring theme is that the globular cluster systems of spirals and…
The properties of old globular cluster systems in galaxy halos are used to infer quantitative constraints on aspects of generic star (cluster) formation. First, the spatial distribution of globulars in three large galaxies, together with…
The central regions of galaxies show the presence of massive black holes and/or dense stellar systems. The question about their modes of formation is still under debate. A likely explanation of the formation of the central dense stellar…