Related papers: Multiple populations in low mass globular clusters…
An increasing amount of spectroscopic and photometric evidence is showing that the stellar populations of globular clusters are not as simple as they have been considered for many years. The presence of at least two different populations of…
Recent work on metal-intermediate globular clusters (GCs) with [Fe/H]=$-1.5$ and $-0.75$ has illustrated the theoretical behavior of multiple populations in photometric diagrams obtained with the James Webb Space Telescope (JWST). These…
This is the second paper in our series about the search for multiple populations in Magellanic Cloud star clusters using the Hubble Space Telescope. Here we report the detection of multiple stellar populations in the colour-magnitude…
We seek to resolve the tension in the literature regarding the presence of radially segregated multiple populations in Galactic globular cluster M13. Previous studies of this nearby cluster have presented discordant results about the degree…
We use high-precision photometry of red-giant-branch (RGB) stars in 57 Galactic globular clusters (GCs), mostly from the `Hubble Space Telescope (HST) UV Legacy Survey of Galactic globular clusters', to identify and characterize their…
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…
Recent advancements in near-infrared (NIR) spectroscopy have opened new opportunities for studying multiple stellar populations in globular clusters (GCs), particularly for newly discovered clusters in the inner Milky Way. While optical…
We present new spectroscopic observations of 5 galaxies, members of the unusually active compact group HCG 16, observed using the Palomar 5m telescope. The high signal to noise ratios (S/N $\sim 70$) of the spectra allow us to study the…
About one-fifth of the Galactic globular clusters (GCs), dubbed Type II GCs, host distinct stellar populations with different heavy elements abundances. NGC 1851 is one of the most studied Type II GCs, surrounded by several controversies…
We present a multiple stellar population (MSP) study of the globular cluster (GC) NGC~6752. We show that our new photometric CN index accurately traces the CN and the nitrogen abundances in cool giants, finding the discrete double red giant…
We present the first evidence of multiple populations in the Galactic globular cluster NGC 6362. We used optical and near-UV Hubble Space Telescope and ground based photometry, finding that both the sub giant and red giant branches are…
Globular cluster systems (GCS) frequently show a bi-modal distribution of the cluster integrated colours. This work explores the arguments to support the idea that the same feature is shared by the diffuse stellar population of the galaxy…
The majority of the inhomogeneities in the chemical composition of Globular Cluster (GC) stars appear due to primordial enrichment by hot-CNO cycled material processed in stars belonging to a first stellar generation. Either massive AGB…
Many scenarios for the origin of the chemical anomalies observed in globular clusters (GCs; i.e., multiple populations) require that GCs were much more massive at birth, up to $10-100\times$, than they are presently. This is invoked in…
[Abridged] Detailed chemical tagging of individual stellar populations in the Galactic globular cluster (GC) NGC 1851 is presented. Abundances are derived from FLAMES spectra for the largest sample of giants (124) ever analysed in this…
Globular clusters show abundance variations for light elements that are not yet well understood. The preferred explanation involves a self-enrichment scenario, with two subsequent generations of stars. Observations of main sequence stars…
In this paper we describe the photometric and spectroscopic properties of multiple populations in seven northern globular clusters. In this study we employ precise ground based photometry from the private collection of Stetson, space…
Nearly all globular clusters (GCs) studied to date show evidence for multiple stellar populations, in stark contrast to the conventional view that GCs are a mono-metallic, coeval population of stars. Building on earlier work, we propose a…
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…
The existence of star-to-star light-element abundance variations in massive Galactic and extragalactic star clusters has fairly recently superseded the traditional paradigm of individual clusters hosting stars with the same age, and uniform…