Related papers: Origin of Extended Star Clusters
The formation of early-type dwarf (dE) galaxies, the most numerous objects in clusters, is believed to be closely connected to the physical processes that drive galaxy cluster evolution, like galaxy harassment and ram-pressure stripping.…
We present a spectroscopic study of the four extended star clusters (ESCs) in NGC 6822 based on the data obtained with Gemini Multi-Object Spectrograph (GMOS) on the Gemini-South 8.1m telescope. Their radial velocities derived from the…
The Galactic Anticenter Stellar Structure (GASS) has been identified with excess surface densities of field stars in several large area sky surveys, and with an unusual, string-like grouping of five globular clusters. At least two of these…
The current properties of globular cluster systems (GCSs) are the result of the evolution experienced by their host galaxies, which shape the richness of the GCS as well as its spatial distribution, among other features. We carry out an…
We analyze the morphological evolution of open clusters and provide shape parameters for 265 open clusters. The results show that the overall shape of sample clusters becomes more elliptical as they grow older, while their core remains…
The ensemble of all star clusters in a galaxy constitutes its star cluster system. In this review, the focus of the discussion is on the ability of star clusters, particularly the systems of old massive globular clusters (GCSs), to mark the…
The origins of most stellar streams in the Milky Way are unknown. With improved proper motions provided by Gaia EDR3, we show that the orbits of 23 Galactic stellar streams are highly clustered in orbital phase space. Based on their…
We investigate the origin of a nearly pointlike cluster of 5 ultrahigh energy cosmic rays at RA ~169.2deg and dec ~56.8deg, using Sloan Digital Sky Survey and other data. No particular source candidates are found near the estimated source…
The origin of young star clusters represents a major challenge for modern stellar astrophysics. While stellar rotation partially explains the colour spread observed along main-sequence turn-offs, i.e. where stars leave the main-sequence…
Shells in Elliptical Galaxies are faint, sharp-edged features, believed to provide evidence of a recent ($\sim 0.5 - 2 \times 10^9$ years ago) merger event. We analyse the Globular Cluster (GC) systems of six shell elliptical galaxies, to…
It is not understood whether long-lived star clusters possess a continuous range of sizes and masses (and hence densities), or if rather, they should be considered as distinct types with different origins. Utilizing the Hubble Space…
UV observations in the local universe have uncovered a population of early-type galaxies with UV flux consistent with low-level recent or ongoing star formation. We present resolved UV-optical photometry of a sample of 19 SDSS early-type…
We probe the evolution of globular clusters that could form in giant molecular clouds within high-redshift galaxies. Numerical simulations demonstrate that the large and dense enough gas clouds assemble naturally in current hierarchical…
We use new models of stellar population synthesis to estimate the fraction of stars formed during the last major bursts of star formation in E/S0 galaxies in low-redshift clusters ($z\simlt0.4$) from the spectral signatures of…
We find a significant number of massive and compact galaxies in clusters from the ESO Distant Clusters Survey (EDisCS) at 0.4<z<1. They have similar stellar masses, ages, sizes and axial ratios to local z~0.04 compact galaxies in WINGS…
Star clusters are often used as tracers of major star formation events in external galaxies as they can be studied up to much larger distances than individual stars. It is vital to understand their evolution if they are used to derive, for…
Recent observations have reported that some gas-rich dwarf irregular (dIrr) galaxies appear to have spherical distributions in the outer underlying old and intermediate-age stellar populations (e.g., NGC 6822). These observations imply that…
We discuss the signature of a peculiar constellation of very massive stars at a projected distance of 2-3 pc around R136a. We discuss various scenarios for its possible origin, such as independent clusters, triggered star formation,…
Using three newly identified galaxy clusters at z~1 (photometric redshift) we measure the evolution of the galaxies within clusters from high redshift to the present day by studying the growth of the red cluster sequence. The clusters are…
Star clusters have long been considered to comprise a simple stellar population, but this paradigm is being challenged, since apart from multiple populations in Galactic globular clusters^{1,2}, a number of intermediate-age star clusters…