Related papers: On the Origin of Cusps in Stellar Systems
We present an equilibrium statistical mechanical theory of collisionless self-gravitational systems with isotropic velocity distributions. Compared to existing standard theories, we introduce two changes: (1) the number of possible…
We use hydrodynamic simulations to examine how the baryonic components of galaxies are assembled, focusing on the relative importance of mergers and smooth accretion in the formation of ~L_* systems. In our primary simulation, which models…
I review recent progress in understanding and modeling galaxy clustering in cosmological simulations, with emphasis on models based on high-resolution dissipationless simulations. During the last decade, significant advances in our…
A brief overview of the properties of massive star clusters in early-type galaxies is given. All ellipticals (with only one known exception) host massive star clusters in the form of globular clusters, suggesting that their formation is…
Stars are thought to form predominantly within filamentary molecular clouds. Recent studies have suggested that active star formation, including the formation of stellar clusters and massive stars, occurs within so-called "hub" structures,…
We investigate evolution of clumpy galaxies with the Hubble Space Telescope (HST) samples of ~17,000 photo-z and Lyman break galaxies at z~0-8. We detect clumpy galaxies with off-center clumps in a self-consistent algorithm that is well…
We investigate the formation of disk-bulge-halo systems by including bulges in the Fall & Efstathiou theory of disk formation. This allows an investigation of bulge dominated disk galaxies, such as S0s and disky ellipticals. The aim of this…
Nuclear star clusters (NSCs) are the densest stellar systems in the Universe. They can be found at the center of all galaxy types, but tend to favor galaxies of intermediate stellar mass around 10$^9\,$M$_{\odot}$[1, 2]. Currently, two main…
Understanding the physical formation of the Hubble sequence remains one of the most important unsolved astrophysical problems. Searches for proto-disks and proto-ellipticals can now be effectively done using deep wide-field Hubble Space…
We study the origin of the diffuse stellar component (DSC) in 117 galaxy clusters extracted from a cosmological hydrodynamical simulation. We identify all galaxies present in the simulated clusters at 17 output redshifts, and then build the…
The discovery of gravitationally lensed stellar clusters at high redshift with the James Webb Space Telescope (JWST) has revealed extremely compact, massive star-forming systems in galaxies at $z > 6$, providing a new window into early…
High-energy, multi-component plasmas in which pair creation and annihilation, lepton-lepton scattering, lepton-proton scattering, and Comptonization all contribute to establishing the particle and photon distributions, are present in a…
Clusters of galaxies are studied from a theoretical point of view, comparing with observational results whenever possible. The problem is approached both analytically as well as by means of high-resoultion numerical simulations. The dark…
We analyze the physical properties and energy balance of density enhancements in two SPH simulations of the formation, evolution, and collapse of giant molecular clouds. In the simulations, no feedback is included, so all motions are due…
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…
In this review, we describe our current understanding of cluster formation: from the general picture of collapse from initial density fluctuations in an expanding Universe to detailed simulations of cluster formation including the effects…
By means of simple numerical models we discuss whether "collisionless stellar evaporation" from cluster elliptical galaxies could be an effective mechanism for the production of intracluster stellar populations. The effectiveness of this…
The nature of compact groups (CGs) of galaxies, apparently so dense that the galaxies often overlap, is still a subject of debate: Are CGs roughly as dense in 3D as they appear in projection? Or are they caused by chance alignments of…
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…
We recently presented a model for the cluster formation efficiency (CFE), i.e. the fraction of star formation occurring in bound stellar clusters. It utilizes the idea that the formation of stars and stellar clusters occurs across a…