Related papers: Has the Universe a honeycomb structure?
A surprisingly large number of galaxies with masses of $\sim10^9-10^{10}M_\odot$ at redshifts of $z\geq9$ are discovered with the James Webb Space Telescope. A possible explanation for the increase in the mass function can be the presence…
An overview of our current understanding of the formation and evolution of star clusters is given, with main emphasis on high-mass clusters. Clusters form deeply embedded within dense clouds of molecular gas. Left-over gas is cleared within…
We present a study of the properties of the star-cluster systems around pseudo-bulges of late-type spiral galaxies using a sample of 11 galaxies with distances from 17 to 37 Mpc. Star clusters are identified from multiband HST ACS and WFPC2…
Using cosmological N-body simulations of critical (SCDM) and open ($\Omega = 0.3$, OCDM) cold dark matter models, we investigate evolution of cluster galaxies. From our numerical simulation, we construct merging history trees of the…
Globular clusters are compact, gravitationally bound systems of up to a million stars. The GCs in the Milky Way contain some of the oldest stars known, and provide important clues to the early formation and continuing evolution of our…
We present a high-resolution simulation of globular cluster formation in a galaxy merger. For the first time in such a simulation, individual star clusters are directly identified and followed on their orbits. We quantitatively compare star…
Galaxies in the Universe are distributed in a web-like structure characterised by different large-scale environments: dense clusters, elongated filaments, sheetlike walls, and under-dense regions, called voids. The low density in voids is…
In gaussian theories of structure formation, the galaxy cluster abundance is an extremely sensitive probe of the density fluctuation power spectrum and of the density parameter, $\Omega$. We develop this theme by deriving and studying in…
Low-mass cluster galaxies are the most common galaxy type in the universe and are at a cornerstone of our understanding of galaxy formation, cluster luminosity functions, dark matter and the formation of large scale structure. I describe in…
We use catalogues of superclusters of galaxies from the 2dF Galaxy Redshift Survey to study the properties of galaxies in superclusters. We compare the properties of galaxies in high and low density regions of rich superclusters, in poor…
Variations in the number of globular clusters per unit galaxy luminosity, which is the specific frequency, and the mass of globular clusters per unit total available mass, are reviewed. Correlations with galaxy luminosity and morphology,…
We follow the evolution of galaxy systems in numerical simulation. Our goal is to understand the role of density perturbations of various scales in the formation and evolution of the cosmic web. We perform numerical simulations with the…
High-mass stars are major players in the chemical and dynamical evolution of galaxies, and young massive clusters are the natural laboratories to study their evolution and their impact on star formation processes. Only in recent years have…
The hot X-ray emitting plasma in galaxy clusters is predicted to have turbulent motions which can contribute around ten percent of the cluster's central energy density. We report deep Chandra X-ray Observatory observations of the Coma…
X-ray observations of clusters at different redshifts are presented and compared. For the nearest cluster -- the Virgo cluster -- we show a comparison of the galaxy distribution and the distribution of the intra-cluster gas. Although the…
The local galaxy distribution offers an interesting constraint to cosmological models of structure formation. The galaxies are distributed in a long, filamentary structure, presumably the result of large amplitude gravitational instability,…
High-spectral resolution observations of clusters of galaxies are a powerful tool to understand the physical processes taking place in these massive objects. Their hot multi-million-degree X-ray emitting cluster atmospheres, containing most…
Populations of young star clusters show significant differences even among "normal" disk galaxies. In this contribution I discuss how properties of young cluster systems are related to those of their host galaxies, based on a recent study…
We study the links between star formation history and structure for a large mass-selected galaxy sample at 0.05 < z_phot < 0.30. The galaxies inhabit a very broad range of environments, from cluster cores to the field. Using HST images, we…
The local Universe displays a rich hierarchical pattern of galaxy clusters and superclusters. The early Universe, however, was almost smooth, with only slight 'ripples' seen in the cosmic microwave background radiation. Models of the…