Related papers: Distortion of Globular Clusters by Galactic Bulges
A massive (~10^2-10^4 Msun) black hole at the center of a globular cluster will tidally disrupt binaries that pass sufficiently close. Such an encounter results in the capture of one binary component by the black hole and ejection of the…
The kinematical and spatial properties of the metal-rich globular clusters in the Galaxy ([Fe/H] > -0.8) indicates that these objects do not comprise a homogeneous population. Three subsystems are identified. The highest-mass clusters…
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…
We first present the results of numerical simulations on formation processes and physical properties of old globular clusters (GCs) located within clusters of galaxies (``intracluster GCs'') and in between clusters of galaxies…
As a first step towards a comprehensive investigation of stellar motions within globular clusters, we present here the results of a study of stellar orbits in a mildly triaxial globular cluster that follows a circular orbit inside a galaxy.…
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…
We use N-body simulations to explore the influence of orbital eccentricity on the dynamical evolution of star clusters. Specifically we compare the mass loss rate, velocity dispersion, relaxation time, and the mass function of star clusters…
The most massive elliptical galaxies show a prominent multi-modality in their globular cluster system color distributions. Understanding the mechanisms which lead to multiple globular cluster sub-populations is essential for a complete…
The Galactic bulge is a tumultuous dense region of space, packed with stars separated by far smaller distances than those in the Solar neighborhood. A quantification of the frequency and proximity of close stellar encounters in this…
The high-density environment of galaxy clusters is ripe for collisional encounters of galaxies. While the large velocity dispersion of clusters was originally thought to preclude slow encounters, the infall of smaller groups into the…
The results of a kinematic study of the Galactic bulge based on spectra of red giants in fields at projected distances of 1.4-1.8 kpc from the Galactic center are presented. There is a marked trend of kinematics with metallicity, in the…
The spatial distribution of compact dark matter in our Galaxy can be determined in a few years of monitoring Galactic globular clusters for microlensing. Globular clusters are the only dense fields of stars distributed throughout the…
Stars in globular clusters can act either as sources for MACHOs (Massive Astrophysical Compact Halo Objects) located along the line of sight or as lenses for more distant background stars. Although the expected rate of microlensing events…
We explore the constraints on globular cluster formation provided by the observed conditions in starbursts where globulars are currently forming, and by the observed properties of young and old globular clusters. We note that the pressure…
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 radial distribution of globular clusters in our Galaxy, M31 and M87 is studied and compared with that of halo stars. The globular cluster distributions seem significantly flatter than those of the stars bulge. Assuming this is a…
Thin stellar streams originating from globular clusters are among the most sensitive tracers of low-mass dark-matter subhalos. Joint analysis of the entire population of stellar streams will place the most robust constraints on the…
Clusters of galaxies are the largest gravitationally-bound objects in the Universe, having diameters on order of Mpc. Our work asked whether their shapes (morphologies) change over time as the Universe ages. We observed a sample of 165…
Thin stellar streams, such as those resulting from the tidal disruption of globular clusters, have long been known and used as probes of the gravitational potential of our Galaxy, both its visible and dark contents. In particular, the…
We study gravitational instabilities in disks, with special attention to the most massive clumps that form because they are expected to be the progenitors of globular-type clusters. The maximum unstable mass is set by rotation and depends…