Related papers: Dynamical Evolution of Globular Clusters in the Ma…
The Ks magnitude distribution of asymptotic giant branch stars provides important constraints on the spatial variation of metallicity and mean-age of the stellar population of galaxies. Here, I present results of the investigation of these…
The oldest and most metal-poor Milky Way stars form a kinematically hot halo, which motivates the two major formation scenarios for our galaxy: extended hierarchical accretion and rapid collapse. RR Lyrae stars are excellent tracers of old…
The rich star clusters in the Large Magellanic Cloud (LMC) are ideal for studying the process of star formation. Here we focus on the determination of age spreads amongst the massive stars in two young clusters, NGC1818 and NGC1805. We…
Blue straggler stars have been proposeed as powerful indicators to measure the dynamical state of Galactic globular clusters. Here we examine for the first time if this framework of blue straggler stars as dynamical clocks, which was…
We investigate effects of time evolution of a rich cluster of galaxies on its member galactic halos in the standard cold dark matter (SCDM) universe using high resolution N-body simulations. We identify several hundred galactic halos within…
Simulations of structure formation in the standard cold dark matter cosmological model quantify the dark matter halos of galaxies. Taking into account dynamical friction between the dark matter halos, we investigate the past orbital…
A few star clusters in the Magellanic Clouds exhibit composite structures in the red-clump region of their colour-magnitude diagrams. The most striking case is NGC419 in the SMC, where the red clump is composed of a main blob as well as a…
We have constructed a large, uniform galaxy cluster catalog from the Sloan Digital Sky Survey data. By studying the morphology--cluster-centric-radius relation, we have found two characteristic environments where galaxy morphologies change…
The formation of populous secondary star cluster systems is a widespread phenomenon in mergers of gas-rich galaxies. Many, if not most, of those clusters are massive and compact enough to be young globular clusters (GCs). GC systems in most…
The Magellanic System harbors >800 expanding shells of neutral hydrogen, providing a unique opportunity for statistical investigations. Most of these shells are surprisingly young, 2--10 Myr old, and correlate poorly with young stellar…
The Large Magellanic Cloud (LMC) has a unique cluster formation history in that nearly all of its globular clusters were formed either $\sim$ 13 Gyr ago or less than $\sim$ 3 Gyr ago. It is not clear what physical mechanism is responsible…
We investigate the influence of the external tidal field of a dark matter halo on the dynamical evolution of star clusters using direct N-body simulations, where we assume that the halo is described by a Navarro, Frenk & White mass profile…
We supplement current evolutionary computations concerning Magellanic Cloud stars by exploring the evolutionary behavior of canonical stellar models (i.e.,with inefficient core overshooting) with metallicities suitable for stars in the…
Most of the globular clusters in the main body of the Galactic halo were formed almost simultaneously. However, globular cluster formation in dwarf spheroidal galaxies appears to have extended over a significant fraction of a Hubble time.…
Globular clusters are large and dense agglomerate of stars. At variance with smaller clusters of stars, they exhibit signs of some chemical evolution. At least for this reason, they are intermediate between open clusters and massive objects…
Recently, very massive compact stellar systems have been discovered in the intracluster regions of galaxy clusters and in the nuclear regions of late-type disk galaxies. It is unclear how these compact stellar systems -- known as…
We present the age distributions for star clusters and individual stars in the Small Magellanic Cloud (SMC) based on data from the Magellanic Clouds Photometric Survey by Zaritsky and collaborators. The age distribution of the SMC clusters…
(Abridged) We investigate the hypothesis that some fraction of the globular clusters presently observed in the Galactic halo formed in external dwarf galaxies, by means of a detailed comparison between Zinn's "old halo", "young halo", and…
Globular clusters (GCs) and many nuclear clusters (NCs) show evidence for hosting multiple generations of stellar populations. Younger stellar populations in NCs appear to reside in disk like structures, including the nuclear cluster in our…
We study the degree of angular substructure in the stellar position distribution of young members of Galactic star-forming regions, looking for correlations with distance from cluster center, surface number density of stars, and local…