Related papers: Evidence for Environmentally Dependent Cluster Dis…
We discuss how contemporary multiwavelength observations of young OB-dominated clusters address long-standing astrophysical questions: Do clusters form rapidly or slowly with an age spread? When do clusters expand and disperse to constitute…
The realization that most stars form in clusters, raises the question of whether star/planet formation are influenced by the cluster environment. The stellar density in the most prevalent clusters is the key factor here. Whether dominant…
Recent images taken with the Hubble Space Telescope (HST) of the interacting disk galaxies NGC 4038/4039 (the Antennae) reveal clusters of many dozens and possibly hundreds of young compact massive star clusters within projected regions…
We present a comparison of late-type galaxies (Sa and later) in intermediate redshift clusters and the field using ACS imaging of four cluster fields: CL0152-1357, CL1056-0337 (MS1054), CL1604+4304, and CL1604+4321. Concentration,…
Open clusters belonging to star-forming complexes are the leftovers from the initial stellar generations. The study of these young systems provides constraints to models of star formation and evolution as well as to the properties of the…
The spectroscopic and photometric signals of the star-to-star abundance variations found in globular clusters seem to be correlated with global parameters like the cluster's metallicity, mass and age. Understanding this behaviour could…
Open clusters have long been used as tracers of Galactic structure. However, without a selection function to describe the completeness of the cluster census, it is difficult to quantitatively interpret their distribution. We create a method…
We present the stellar mass-size relations for elliptical, lenticular, and spiral galaxies in the field and cluster environments using HST/ACS imaging and data from the Space Telescope A901/2 Galaxy Evolution Survey (STAGES). We use a large…
The goal of the Local Cluster Survey is to look for evidence of environmentally driven quenching among star-forming galaxies in nearby galaxy groups and clusters. Quenching is linked with environment and stellar mass, and much of the…
The Magellanic Clouds host a large population of massive (> 10^4 Msun) star clusters with ages ranging from a few Myr to 12 Gyr. In nearly all cases, close inspection of their CMDs reveals features that deviate from expectations of a…
Star clusters are ideal tracers of star formation activity in systems outside the volume that can be studied using individual, resolved stars. These unresolved clusters span orders of magnitude in brightness and mass, and their formation is…
We present new spectroscopic observations of the stellar cluster population of region B in the prototype starburst galaxy M82 obtained with the Gillett Gemini-North 8.1-metre telescope. By coupling the spectroscopy with UBVI photometry…
Multi-color photometry of the stellar populations in five fields in the third Galactic quadrant centred on the clusters NGC 2215, NGC 2354, Haffner 22, Ruprecht 11, and ESO489SC01 is interpreted in terms of a warped and flared Galactic…
Spectral line indices for a sample of 290 nearby E and S0 galaxies are used to investigate the stellar populations of these galaxies. Relations are established between the line indices (Mg2, <Fe>, Hbeta) and the velocity dispersions, the…
A majority of massive stars are part of binary systems, a large fraction of which will inevitably interact during their lives. Binary-interaction products (BiPs), i.e. stars affected by such interaction, are expected to be commonly present…
Stromgren uvby CCD photometry can be used in a variety of ways to constrain the absolute and relative ages of globular clusters. The reddening corrected (v-y, c1) diagram offers the means to derive ages that are completely independent of…
We present first results from a high resolution multi-band survey of the Westerlund 2 region with the Hubble Space Telescope. Specifically, we imaged Westerlund 2 with the Advanced Camera for Surveys through the $F555W$, $F814W$, and…
We review the properties of massive star evolution in different environments, where the major environmental factor is metallicity. Comparisons between evolutionary models and observations of massive OB, WR stars and related objects are…
In this paper, using 2MASS photometry, we study the mass functions $\phi(M) = dN/dM \propto M^{-\alpha}$ of a sample of nine clusters of ages varying from 4 Myr--1.2 Gyr and Galactocentric distances from 6--12 kpc. We look for evidence of…
We study the impact of local environment on the transformation of spiral galaxies in three nearby ($z < 0.08$) Abell clusters: A85/A496/A2670. These systems were observed in HI with the Very Large Array, covering a volume extending beyond…