Related papers: Dynamics versus structure: breaking the density de…
We present numerical simulations of planetary systems in star clusters with different initial stellar densities, to investigate the impact of the density on debris disc dynamics. We use LPS+ to combine N-body codes NBODY6++GPU and REBOUND…
We investigate the evolution of the star formation rate in the early Galaxy using beryllium and oxygen abundances in metal poor stars. Specifically, we show that stars belonging to two previously identified kinematical classes (the…
How starburst clusters form out of molecular clouds is still an open question. In this article, I highlight some of the key constraints in this regard, that one can get from the dynamical evolutionary properties of dense stellar systems. I…
This paper studies the dynamical evolution of young stellar clusters with $N$ = 100 - 1000 members. We use N-body simulations to explore how evolution depends on system size $N$ and the initial conditions. Motivated by recent observations…
Our current understanding of the physical processes of star formation is reviewed, with emphasis on processes occurring in molecular clouds like those observed nearby. The dense cores of these clouds are predicted to undergo gravitational…
Both simulations and observations indicate that stars form in filamentary, hierarchically clustered associations, most of which disperse into their galactic field once feedback destroys their parent clouds. However, during their early…
We have investigated how the incidence of star-forming galaxies varies with the environment using a volume-limited sample of nearby galaxy spectra extracted from the 2dF Galaxy Redshift Survey. The environment is characterized by the local…
Planets are observed to orbit the component star(s) of stellar binary systems on so-called circumprimary or circumsecondary orbits, as well as around the entire binary system on so-called circumbinary orbits. Depending on the orbital…
Using our recently improved Monte Carlo evolution code, we study the evolution of the binary fraction in globular clusters. In agreement with previous N-body simulations, we find generally that the hard binary fraction in the core tends to…
Many, possibly most, stars form in binary and higher-order multiple systems. Therefore, the properties and frequency of binary systems provide strong clues to the star-formation process, and constraints on star-formation models. However,…
Wide gravitationally bound pairs of stars can be formed from adjacent prestellar cores that happen to move slowly enough relative to each other. These binaries are remnants of the primordial clustering. It is shown that the expected…
The fragmentation process of primordial-gas cores during prestellar collapse is studied using three-dimensional nested-grid hydrodynamics. Starting from the initial central number density of n \sim10^3 cm^-3, we follow the evolution of…
At $z\sim2$, star-formation activity is thought to be high even in high-density environments such as galaxy clusters and proto-clusters. One of the critical but outstanding issues is if structural growth of star-forming galaxies can differ…
The young star clusters we observe today are the building blocks of a new generation of stars and planets in our Galaxy and beyond. Despite their fundamental role we still lack knowledge about the conditions under which star clusters form…
The solar system was most likely born in a star cluster containing at least 1000 stars. It is highly probable that this cluster environment influenced various properties of the solar system like its chemical composition, size and the…
We present a study of the variation of spatial structure of stellar populations within dwarf galaxies as a function of the population age. We use deep Hubble Space Telescope/Advanced Camera for Surveys imaging of nearby dwarf galaxies in…
We study the circumstances under which first collisions occur in young and dense star clusters. The initial conditions for our direct $N$-body simulations are chosen such that the clusters experience core collapse within a few million…
We investigate the formation of both clustered and distributed populations of young stars in a single molecular cloud. We present a numerical simulation of a 10,000 solar mass elongated, turbulent, molecular cloud and the formation of over…
The majority of stars in known star-forming regions are located in binary systems. Although the separation distribution of these populations varies from one region to another, most peak between a few and several tens of AU. Given the >100…
We examine the spatial distribution and mass segregation of dense molecular cloud cores in a number of nearby star forming regions that span about four orders of magnitude in star formation activity. We use an approach based on the…