Related papers: An Expanding Trapezium Cluster?
Massive stars rapidly change their masses through strong stellar winds and mass transfer in binary systems. We show that such mass changes leave characteristic signatures in stellar mass functions of young star clusters which can be used to…
Observations and theory both suggest that star clusters form sub-virial (cool) with highly sub-structured distributions. We perform a large ensemble of N-body simulations of moderate-sized (N=1000) cool, fractal clusters to investigate…
A significant fraction of stars in globular clusters (about 70%-85%) exhibit peculiar chemical patterns with strong abundance variations in light elements along with constant abundances in heavy elements. These abundance anomalies can be…
The binary fraction in young open clusters exceeds that of field stars, making the study of binary dynamical evolution in clusters essential for understanding the origins and evolution of field binaries. Using N-body simulations based on…
I present a simplified analytical model that simulates the evolution of the binary population in a dynamically evolving globular cluster. A number of simulations have been run spanning a wide range in initial cluster and environmental…
Multiplicity among massive stars represents a major uncertainty in stellar evolution theory, because the extra physical processes that it introduces significantly impacts each star's structure. While multiplicity of O-type stars is fairly…
Young binaries within dense molecular clouds are subject to dynamical friction from ambient gas. Consequently, their orbits decay, with both the separation and period decreasing in time. A simple analytic expression is derived for this…
We present a high spatial resolution UV to NIR survey of 44 young binary stars in Taurus with separations of 10-1000 AU. The primary results include: (1) The relative ages of binary star components are more similar than the relative ages of…
N-body simulations give us a rough idea of how the shape of a simulated object appears in three-dimensional space. From an observational point of view this may give us a misleading picture. The faint stars may be the most common stars in…
The population statistics of binary stars are an important output of star formation models. However populations of wide binaries evolve over time due to interactions within a system's birth environment and the unfolding of wide,…
(abridged) We use newly available empirical binary fractions for globular clusters to carry out a direct test of the binary evolution hypothesis, and of collisional channels that involve binary stars. More specifically, using the previously…
We perform N-body simulations of a cluster that forms in a dwarf galaxy and is then accreted by the Milky Way to investigate how a cluster's structure is affected by a galaxy merger. We find that the cluster's half mass radius will respond…
We present a new wide field image of the distant cluster AC114 ($z=0.31$) obtained with Wide Field and Planetary Camera II onboard the Hubble Space Telescope. This image considerably extends our knowledge of the lensing properties of the…
The massive (13,000-26,000 Msolar), young (15-30 Myr) Large Magellanic Cloud star cluster NGC 1818 reveals an unexpected increasing binary frequency with radius for F-type stars (1.3-2.2 Msolar). This is in contrast to many older star…
The clustered nature of star formation should produce a high degree of structure in the combined phase and chemical space in the Galactic disk. To date, observed structure of this kind has been mostly limited to bound clusters and moving…
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…
Context. Rotational instability of rubble-pile asteroids can trigger mass shedding, forming transient debris clouds that may provide the initial conditions for secondary formation in binary systems. Aims. We investigate the dynamical and…
The total mass of distant star clusters is often derived from the virial theorem, using line-of-sight velocity dispersion measurements and half-light radii. Although most stars form in binary systems, this is mostly ignored when…
We show how observations of the evolution of the galaxy cluster number abundance can be used to constrain primordial non-Gaussianity in the universe. We carry out a maximum likelihood analysis incorporating a number of current datasets and…
We report the formation of bound star clusters in a sample of high-resolution cosmological zoom-in simulations of z>5 galaxies from the FIRE project. We find that bound clusters preferentially form in high-pressure clouds with gas surface…