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Related papers: Neutron-capture elements in NGC 6752 multiple popu…

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New elemental abundances for the neutron-capture elements Sr, Nb, Mo, Ru, La, Sm, and Eu are presented for a large sample of 180 barium (Ba) giant stars, a class of chemically peculiar objects that exhibit in their spectra enhancements of…

Solar and Stellar Astrophysics · Physics 2021-08-19 M. P. Roriz , M. Lugaro , C. B. Pereira , C. Sneden , S. Junqueira , A. I. Karakas , N. A. Drake

We present the abundance analysis of stars from the tip of the red giant branch (RGB) to below the RGB-bump in the globular cluster NGC 2808, based on high resolution echelle spectra. We derived abundances of Al, alpha-process elements (Si…

Astrophysics · Physics 2009-11-11 Eugenio Carretta

Our understanding of multiple populations in globular clusters (GCs) largely comes from photometry and spectroscopy: appropriate photometric diagrams can disentangle first and second populations (1P and 2P)-1P having chemical signatures…

There is a growing body of evidence for the presence of multiple stellar populations in some globular clusters, including NGC 1851. For most of these peculiar globular clusters, however, the evidence for the multiple red giant-branches…

Astrophysics of Galaxies · Physics 2014-11-20 Sang-Il Han , Young-Wook Lee , Seok-Joo Joo , Sangmo Tony Sohn , Suk-Jin Yoon , Hak-Sub Kim , Jae-Woo Lee

We present a new method to estimate the fraction of stars with chemical composition of first and second(s) generation(s) currently hosted in Galactic globular clusters (GCs). We compare cluster and field stars of similar metallicity in the…

Astrophysics of Galaxies · Physics 2015-06-16 Eugenio Carretta

Pseudo two-colour diagrams or Chromosome maps (ChM) indicate that NGC 2808 host five different stellar populations. The existing ChMs have been derived by the Hubble Space Telescope photometry, and comprise of stars in a small field of view…

Context. Globular clusters host multiple populations of long-lived low-mass stars whose origin remains an open question. Several scenarios have been proposed to explain the associated photometric and spectroscopic peculiarities. They…

Solar and Stellar Astrophysics · Physics 2016-08-17 William Chantereau , Corinne Charbonnel , Georges Meynet

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

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…

Astrophysics of Galaxies · Physics 2015-05-27 Charlie Conroy

Globular Clusters (GCs) are natural laboratories where stellar and chemical evolution can be studied in detail. In addition, their chemical patterns and kinematics can tell us wich Galactic structure (Disk, Bulge, Halo or extragalactic) the…

Solar and Stellar Astrophysics · Physics 2018-01-10 A. Mura-Guzmán , S. Villanova , C. Muñoz , B. Tang

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…

Astrophysics · Physics 2008-11-24 Eugenio Carretta , Angela Bragaglia , Raffaele G. Gratton , Sara Lucatello

(Abridged) Globular clusters host multiple stellar populations showing different sodium enrichments. These various populations can be observed along the main sequence, red giant and horizontal branch phases. Recently it was shown, however,…

Solar and Stellar Astrophysics · Physics 2015-06-17 Corinne Charbonnel , William Chantereau , Thibaut Decressin , Georges Meynet , Daniel Schaerer

We present the homogeneous abundance analysis for a combined sample of 185 giants in the bulge globular cluster (GC) NGC 6388. Our results are used to describe the multiple stellar populations and differences or analogies with bulge field…

Astrophysics of Galaxies · Physics 2023-09-06 Eugenio Carretta , Angela Bragaglia

The determination of heavy element abundances from planetary nebula (PN) spectra provides an exciting opportunity to study the nucleosynthesis occurring in the progenitor asymptotic giant branch (AGB) star. We perform post-processing…

Solar and Stellar Astrophysics · Physics 2015-05-14 Amanda I. Karakas , Maria Lugaro

Metal-poor stars in the Galactic halo often show strong enhancements in carbon and/or neutron-capture elements. However, the Galactic bulge is notable for its paucity of carbon-enhanced metal-poor (CEMP) and/or CH-stars, with only two such…

Astrophysics of Galaxies · Physics 2019-02-13 A. Koch , M. Reichert , C. J. Hansen , M. Hampel , R. J. Stancliffe , A. Karakas , A. Arcones

We numerically investigate abundance properties of the Galactic globular clusters (GCs) by adopting a new ``external pollution'' scenario. In this framework, GCs are assumed to originate in forming low-mass dwarfs embedded in dark matter…

Astrophysics · Physics 2008-11-26 K. Bekki , S. W. Campbell , J. C. Lattanzio , J. E. Norris

We report on observations of six giants in the globular cluster M15 (NGC 7078) using the Subaru Telescope to measure neutron-capture elemental abundances. Our abundance analyses based on high-quality blue spectra confirm the star-to-star…

Astrophysics · Physics 2009-11-11 Kaori Otsuki , Satoshi Honda , Wako Aoki , Toshitaka Kajino , Grant J. Mathews

The [Sr/Ba] and [Y/Ba] scatter observed in some galactic halo stars that are very metal-poor stars and in a few individual stars of the oldest known Milky Way globular cluster NGC 6522,have been interpreted as evidence of early enrichment…

Solar and Stellar Astrophysics · Physics 2015-06-22 B. Barbuy , C. Chiappini , E. Cantelli , E. Depagne , M. Pignatari , R. Hirschi , G. Cescutti , S. Ortolani , V. Hill , M. Zoccali , D. Minniti , M. Trevisan , E. Bica , A. Gómez

Stars in globular clusters (GCs) exhibit a peculiar chemical pattern with strong abundance variations in light elements along with a constant abundance in heavy elements. These abundance anomalies can be explained by a primordial pollution…

Astrophysics · Physics 2009-11-13 T. Decressin , H. Baumgardt , P. Kroupa