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Related papers: A JWST project on 47 Tucanae. Binaries among multi…

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The determination of the Ba abundance in globular cluster (GC) stars is a very powerful test to address several issues in the framework of multiple population scenarios. We measured the Ba content for a sample of more than 1200 stars in 15…

Solar and Stellar Astrophysics · Physics 2015-05-19 Valentina D'Orazi , Raffaele Gratton , Sara Lucatello , Eugenio Carretta , Angela Bragaglia , Anna F. Marino

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…

Astrophysics of Galaxies · Physics 2015-08-19 Nate Bastian , Carmela Lardo

Spreads in light element abundances among stars (a.k.a. multiple populations) are observed in nearly all globular clusters. One way to map such chemical variations using high-precision photometry is to employ a suitable combination of…

Solar and Stellar Astrophysics · Physics 2018-09-12 Carmela Lardo , Maurizio Salaris , Nate Bastian , Alessio Mucciarelli , Emanuele Dalessandro , Ivan Cabrera-Ziri

We have investigated the effect of the number of primordial binaries on the relationship between the total number of detected binaries within globular cluster and its collision rate. We have used simulated populations of binary stars in…

Astrophysics · Physics 2009-11-10 B. Gendre

We investigate the binary content of the two stellar populations that coexist in the globular cluster NGC 3201. Previous studies of binary stars in globular clusters have reported higher binary fractions in their first populations (P1,…

Binary populations in young star clusters show multiplicity fractions both lower and up to twice as high as those observed in the Galactic field. We follow the evolution of a population of binary stars in dense and loose star clusters…

Astrophysics of Galaxies · Physics 2015-06-05 Michael Marks , Pavel Kroupa

We present the result of a survey of Monte Carlo simulations of globular clusters hosting two generations of stars including a large (f_b=50%) fraction of primordial binaries in both populations. The dynamical evolution of the two stellar…

Solar and Stellar Astrophysics · Physics 2022-03-14 A. Sollima , R. Gratton , S. Lucatello , E. Carretta

The HST UV Survey of Globular Clusters (GCs) has investigated GCs and their stellar populations. In previous papers of this series we have introduced a pseudo two-color diagram, "chromosome map" (ChM), that maximises the separation between…

Solar and Stellar Astrophysics · Physics 2019-05-29 A. F. Marino , A. P. Milone , A. Renzini , F. D'Antona , J. Anderson , L. R. Bedin , A. Bellini , G. Cordoni , E. P. Lagioia , G. Piotto , M. Tailo

The dynamical evolution of globular clusters (GCs) is tied to their binary population, as binaries segregate to the cluster centre, leading to an increased binary fraction in the core. This central overabundance of mainly hard binaries can…

Most Globular Clusters so far examined host (at least) two stellar populations. This feature requires a two--step process, in which the nuclearly processed matter from a first generation (FG) of stars gives birth to a second generation (SG)…

Astrophysics of Galaxies · Physics 2015-05-28 V. Caloi , F. D'Antona

Wide-field photometry of Galactic globular clusters (GCs) has been investigated to overcome limitations from the small field of view of the Hubble Space Telescope in the study of multiple populations. In particular, 'chromosome maps' (ChMs)…

We study the evolution of binary stars in globular clusters using a novel approach combining a state-of-the-art population synthesis code with a simple treatment of dynamical interactions in the dense cluster core. We find that the…

Astrophysics · Physics 2007-05-23 N. Ivanova , K. Belczynski , J. M. Fregeau , F. A. Rasio

We have obtained high resolution (<1") deep x-ray images of the globular cluster 47Tucanae (NGC 104) with the Chandra X-ray Observatory to study the population of compact binaries in the high stellar density core. A 70 kilosec exposure of…

Astrophysics · Physics 2019-08-17 Jonathan E. Grindlay , Craig Heinke , Peter D. Edmonds , Stephen S. Murray

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…

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…

Astrophysics · Physics 2009-11-13 F. D'Antona , V. Caloi

Many galactic globular clusters (GCs) contain at least two stellar populations. Recent observational studies found that the radial distributions of the first (P1) and second population (P2) differ in dynamically-young GCs. Since P2 is…

We have used a set of archived Hubble Space Telescope/ACS images to probe the evolved populations of the globular cluster 47 Tucanae. We find an excess of Asymptotic Giant Branch (AGB) stars in the cluster core. We interpret this feature as…

Astrophysics · Physics 2009-11-11 Giacomo Beccari , Francesco R. Ferraro , Barbara Lanzoni , Michele Bellazzini

Globular Cluster (GC) systems of most early-type galaxies show bimodal optical color distributions, yet their Luminosity Functions (LFs) look like simple Gaussians with turn-over magnitudes used for determination of distances and the Hubble…

Astrophysics · Physics 2009-11-10 Uta Fritze -- v. Alvensleben

Globular clusters (GCs) are evolved stellar systems containing entire populations of millisecond pulsars (MSPs), which are efficient gamma-ray emitters. Observations of this emission can be used as a powerful tool to explore the dynamical…

High Energy Astrophysical Phenomena · Physics 2019-04-10 Raniere de Menezes , Fabio Cafardo , Rodrigo Nemmen

Binary stars are common in star clusters and galaxies, but the detailed effects of binary evolution are not taken into account in some colour-magnitude diagram (CMD) studies. This paper studies the CMDs of twelve globular clusters via…

Solar and Stellar Astrophysics · Physics 2015-06-12 Zhongmu Li , Caiyan Mao , Ruheng Li , Ruxi Li , Maocai Li