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Several recent studies have reported the detection of an anomalous color spread along the red giant branch (RGB) of some globular clusters (GC) that appears only when color indices including a near ultraviolet band (such as Johnson U or…

Astrophysics of Galaxies · Physics 2015-05-20 C. Lardo , M. Bellazzini , E. Pancino , E. Carretta , A. Bragaglia , E. Dalessandro

We present homogeneous abundances for Fe and some of the elements involved in the proton-capture reactions (O, Na, Mg, Al, and Si) for 202 red giants in 17 Galactic globular clusters (GCs) from the analysis of high resolution UVES spectra…

Astrophysics of Galaxies · Physics 2015-05-14 Eugenio Carretta , Angela Bragaglia , Raffaele Gratton , Sara Lucatello

We present chemical abundance analysis of a sample of 15 red giant branch (RGB) stars of the Globular Cluster NGC~1851 distributed along the two RGBs of the (v, v-y) CMD. We determined abundances for C+N+O, Na, $\alpha$, iron-peak, and…

Astrophysics of Galaxies · Physics 2015-05-19 Sandro Villanova , Douglas Geisler , Giampaolo Piotto

The chemical composition of multiple populations in the massive globular cluster (GC) NGC~2808 is addressed with the homogeneous abundance re-analysis of 140 red giant branch (RGB) stars. UVES spectra for 31 stars and GIRAFFE spectra for…

Solar and Stellar Astrophysics · Physics 2015-09-23 Eugenio Carretta

We present CH and CN index analysis and C and N abundance calculations based on the low-resolution blue spectra of red giant branch (RGB) stars in the Galactic globular cluster NGC 7089 (M 2). Our main goal is to investigate the C-N…

Solar and Stellar Astrophysics · Physics 2015-06-11 C. Lardo , E. Pancino , A Mucciarelli , A. P. Milone

It is now clear that abundance variations from star-to-star among the light elements, particularly C, N, O, Na and Al, are ubiquitous within galactic globular clusters; they appear seen whenever data of high quality is obtained for a…

Astrophysics · Physics 2007-05-23 Judith G. Cohen

We present radial velocities and chemical abundances of O, Na, Mg, Al, Si, Ca, Cr, Fe, Co, Ni, and Cu for a sample of 156 red giant branch stars in two Galactic bulge fields centered near (l,b)=(+5.25,-3.02) and (0,-12). The (+5.25,-3.02)…

Solar and Stellar Astrophysics · Physics 2015-06-22 Christian I. Johnson , R. Michael Rich , Chiaki Kobayashi , Andrea Kunder , Andreas Koch

We present a chemical composition analysis of 36 giant stars in the mildly metal-poor globular cluster M5 (NGC 5904). The analysis makes use of high resolution data acquired at the Keck I telescope as well as a re-analysis of high…

[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…

Solar and Stellar Astrophysics · Physics 2015-05-28 Eugenio Carretta , Sara Lucatello , Raffaele Gratton , A. Bragaglia , Valentina D'Orazi

Context. Globular clusters are considered key objects for understanding the formation and evolution of the Milky Way. In this sense, their characterisation in terms of their chemical and orbital parameters can provide constraints to the…

Astrophysics of Galaxies · Physics 2024-02-12 J. Schiappacasse-Ulloa , S. Lucatello , G. Cescutti , E. Carretta

The FLAMES survey ``Na-O anti-correlation and HB" uncovered the modern standard for globular clusters (GCs), that is their ubiquitous multiple stellar populations (MPs) distinct by the abundance of proton-capture elements. That survey can…

Solar and Stellar Astrophysics · Physics 2026-03-25 Eugenio Carretta

We measure chemical abundances for over 20 elements of 15 N-rich field stars with high resolution ($R \sim 30000$) optical spectra. We find that Na, Mg, Al, Si, and Ca abundances of our N-rich field stars are mostly consistent with those of…

Astrophysics of Galaxies · Physics 2021-06-02 Jincheng Yu , Baitian Tang , J. G. Fernandez-Trincado , Douglas Geisler , Hongliang Yan , M. Soto

Studying the abundances in metal-poor globular clusters is crucial for understanding the formation of the Galaxy and the nucleosynthesis processes in the early Universe. We observed 13 red giant stars from the metal-poor globular cluster…

Solar and Stellar Astrophysics · Physics 2025-05-08 Avrajit Bandyopadhyay , Rana Ezzeddine , Vinicius M. Placco , Anna Frebel , David S Aguado , Ian U. Roederer

Homogeneous abundances of light elements, alpha and Fe-group elements from high-resolution FLAMES spectra are presented for 76 red giant stars in M54, a massive globular cluster (GC) lying in the nucleus of the Sagittarius dwarf galaxy. We…

Astrophysics of Galaxies · Physics 2015-05-19 E. Carretta , A. Bragaglia , R. G. Gratton , S. Lucatello , M. Bellazzini , G. Catanzaro , F. Leone , Y. Momany , G. Piotto , V. D'Orazi

We analyse the abundance ratios of the light elements Mg, Ca, C and N, relative to Fe, for 147 red-sequence galaxies in the Coma cluster and the Shapley Supercluster. The sample covers a six-magnitude range in luminosity, from giant…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 Russell J. Smith , John R. Lucey , Michael J. Hudson , Terry J. Bridges

We have analyzed high-resolution and high signal-to-noise ratio optical spectra of nearby FGK stars with and without detected giant planets in order to homogeneously measure their photospheric parameters, mass, age, and the abundances of…

Solar and Stellar Astrophysics · Physics 2015-07-29 R. da Silva , A. C. Milone , H. J. Rocha-Pinto

We present detailed abundance measurements for 45 globular clusters (GCs) in galaxies in (and, in one case, beyond) the Local Group. The measurements are based on new high-resolution integrated-light spectra of GCs in NGC 185, NGC 205, M31,…

Astrophysics of Galaxies · Physics 2022-04-20 S. S. Larsen , P. Eitner , E. Magg , M. Bergemann , C. A. S. Moltzer , J. P. Brodie , A. J. Romanowsky , J. Strader

We use our new, flux-calibrated stellar population model of absorption-line indices to derive ages, metallicities, and various element abundance ratios from integrated light spectroscopy of galactic globular clusters. The ages agree well…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 Daniel Thomas , Jonas Johansson , Claudia Maraston

The origin of the star-to-star abundance variations found for the light elements in Galactic globular clusters (GGCs) is not well understood, which is a significant problem for stellar astrophysics. While the light element abundance…

Solar and Stellar Astrophysics · Physics 2019-01-23 C. Salgado , G. S. Da Costa , J. E. Norris , D. Yong

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