Related papers: In search of massive single-population Globular Cl…
We review the multiple population (MP) phenomenon of globular clusters (GCs): i.e., the evidence that GCs typically host groups of stars with different elemental abundances and/or distinct sequences in photometric diagrams. Most Galactic…
The majority of spiral and elliptical galaxies in the Universe host very dense and compact stellar systems at their centres known as nuclear star clusters (NSCs). In this work we study the stellar populations and star formation histories…
We investigate the long-term dynamical evolution of two distinct stellar populations of low-mass stars in globular clusters in order to study whether the energy equipartition process can explain the high number of stars harbouring abundance…
In the past decade, the notion that globular clusters (GCs) are composed of coeval stars with homogeneous initial chemical compositions has been challenged by growing evidence that they host an intricate stellar population mix, likely…
We present the first results from the analysis of GIRAFFE spectra of more than 1200 red giants stars in 19 Galactic Globular Clusters (GCs), to study the chemical composition of second generation stars and their link with global cluster…
Almost all globular clusters (GCs) contain multiple populations consisting of stars with varying helium and light-element abundances. These populations include first-population stars, which exhibit similar chemical compositions to…
In this paper, I review some of the basic properties of the pulsar population in globular clusters (GCs) and compare it with the the Galactic disk population. The neutron stars (NSs) in GCs were likely formed - and appear to continue…
Recent progress in studies of globular clusters has shown that they are not simple stellar populations, being rather made of multiple generations. Evidence stems both from photometry and spectroscopy. A new paradigm is then arising for the…
Recent observations have revealed that at least several old globular clusters (GCs) in the Galaxy have discrete distributions of stars along the Mg-Al anti-correlation. In order to discuss this recent observation, we construct a new…
We use Cycle 21 Hubble Space Telescope (HST) observations and HST archival ACS Treasury observations of 30 Galactic Globular Clusters to characterize two distinct stellar populations. A sophisticated Bayesian technique is employed to…
Globular clusters (GCs) display much lower binary fractions than found among main-sequence stars in the solar neighborhood. The physical cause of this difference is debatable: does it reflect different star formation outcomes at low…
The star-to-star differences in the abundance of light elements observed in the globular clusters (GCs) can be explained assuming that a second generation (SG) of stars form in the gas ejected by the asymptotic giant branch (AGB) stars…
Globular Clusters (GCs) and Nuclear Star Clusters (NSCs) are typically composed by several stellar populations, characterized by different chemical compositions. Different populations show different ages in NSCs but not necessarily in GCs.…
There is compelling observational evidence that globular clusters (GCs) are quite complex objects. A growing body of photometric results indicate that the evolutionary sequences are not simply isochrones in the observational plane -as…
All globular clusters (GCs) studied to date show evidence for internal variation in their light element abundances. These variations have been interpreted as evidence for multiple star formation episodes within GCs, with secondary episodes…
While chemical composition spreads are now believed to be a universal characteristic of globular clusters (GCs), not all of them present multiple populations in their color-magnitude diagrams (CMDs). Here we present a new scenario for the…
Recent work, based on data from the Hubble Space Telescope (HST) UV Legacy Survey of Galactic Globular Clusters (GCs), has revealed that all the analyzed clusters host two groups of first- (1G) and second-generation (2G) stars. In most GCs,…
The majority of the inhomogeneities in the chemical composition of Globular Cluster (GC) stars appear due to primordial enrichment. The most studied model today claims that the ejecta of Asymptotic Giant Branch (AGB) stars of high mass…
We investigate the formation processes of the Galactic globular cluster (GC) omega Cen with multiple stellar populations based on our original hydrodynamical simulations with chemical enrichment by Type II supernovae (SNe II), asymptotic…
We studied the metal-poor globular cluster (GC) populations of a large variety of galaxies (47 galaxies spanning about 10mag in absolute brightness) and compared their mean [Fe/H] with the properties of the host galaxies. The mean [Fe/H] of…