Related papers: Disentangling multiple stellar populations in glob…
This paper is aimed at emphasizing some of the main hints, constraints and difficulties we currently have in trying to understand how globular clusters formed, along with their multiple stellar generations, an issue that must be regarded as…
Multiple stellar populations are a widespread phenomenon among Galactic globular clusters. Even though the origin of the enriched material from which new generations of stars are produced remains unclear, it is likely that self-enrichment…
Variations in the photometric parameters of stellar systems as a function of their evolution and the stellar populations comprising them are investigated. A set of seven evolutionary models with an exponential decrease in the star-formation…
Globular clusters are valuable fossil records of the formation and evolution of their host galaxies. The color distribution of elliptical galaxy globular cluster systems indicates an episodic formation history, consistent with a merger…
New and archival HST images of the globular cluster systems of 17 relatively nearby galaxies and 6 more distant galaxies have been used to establish the characteristics of GC subpopulations over a range of host galaxy morphological type…
We discuss some of the key open questions regarding the formation and evolution of globular clusters (GCs) during galaxy formation and assembly within a cosmological framework. The current state-of-the-art for both observations and…
Our recent CCD photometry (Lee et al. 1999) has shown, for the first time, that omega Cen has several distinct stellar populations, which is reminiscent of the Sagittarius dwarf galaxy. Here we present more detailed analysis of the data…
We discuss in detail the pulsation properties of variable stars in globular clusters (GCs) and in Local Group (LG) dwarf galaxies. Data available in the literature strongly support the evidence that we still lack a complete census of…
I present the first evidence of multiple populations in the globular cluster (GCs) 47Tucanae based on images collected with the near-infrared camera (NIRCam) on board the James Webb Space Telescope (JWST). While NIRCam photometry is poorly…
Blue Straggler stars are present in all the properly observed Globular Clusters. They mimic a rejuvenated stellar population and their existence has been a puzzle for many years. We performed an extensive spectroscopic survey of the surface…
In gaussian theories of structure formation, the galaxy cluster abundance is an extremely sensitive probe of the density fluctuation power spectrum and of the density parameter, $\Omega$. We develop this theme by deriving and studying in…
Numerous observational studies have revealed the ubiquitous presence of multiple stellar populations in globular clusters and cast many hard challenges for the study of the formation and dynamical history of these stellar systems. In this…
The physical properties of star cluster populations offer valuable insights into their birth, evolution, and disruption. However, individual stars in clusters beyond the nearest neighbours of the Milky Way are unresolved, forcing analyses…
The Hubble Space Telescope UV Legacy Survey of Galactic Globular Clusters is providing a major breakthrough in our knowledge of Globular Clusters (GCs) and their stellar populations. Among the main results, we discovered that all the…
Hubble Space Telescope (HST) photometry is providing an extensive analysis of globular clusters (GCs). In particular, the pseudo two-colour diagram dubbed 'chromosome map (ChM)' allowed to detect and characterize their multiple populations…
The discovery of the Sagittarius dwarf galaxy, which is being tidally disrupted by and merging with the Milky Way, supports the view that the halo of the Galaxy has been built up at least partially by the accretion of similar dwarf systems.…
In the first part of this article, we review observations of the mass and luminosity functions of young and old star cluster systems. We also review some of the physical processes that may determine the characteristic mass of globular…
Many, possibly most, stars form in binary and higher-order multiple systems. Therefore, the properties and frequency of binary systems provide strong clues to the star-formation process, and constraints on star-formation models. However,…
Globular clusters are compact, gravitationally bound systems of up to a million stars. The GCs in the Milky Way contain some of the oldest stars known, and provide important clues to the early formation and continuing evolution of our…
Evolutionary synthesis models for star clusters of various metallicities including gaseous emission during the lifetime of the ionising stars are used to model star cluster systems comprising two populations: an old metal-poor globular…