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Related papers: Abundances of iron-peak elements in 58 bulge spher…

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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

Stars born from the same molecular cloud should be nearly homogeneous in their element abundances. The concept of chemical tagging is to identify members of disrupted clusters by their clustering in element abundance space. Chemical tagging…

Astrophysics of Galaxies · Physics 2016-01-11 Yuan-Sen Ting , Charlie Conroy , Hans-Walter Rix

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 present the first detailed chemical abundances for seven GD-1 stream stars from Subaru/HDS spectroscopy. Atmospheric parameters were derived via color calibrations ($T\rm_{eff}$) and iterative spectroscopic analysis. LTE abundances for…

We have derived new detailed abundances of Mg, Ca, and the Fe-group elements Sc through Zn (Z = 21-30) for 37 main sequence turnoff very metal-poor stars ([Fe/H] <= -2.1). We analyzed Keck HIRES optical and near-UV high signal-to-noise…

The chemical evolution of neutron capture elements in the Milky Way is still a matter of debate. Although more and more studies investigate their chemical behaviour, there is still a lack of a significant large sample of abundances of a key…

Solar and Stellar Astrophysics · Physics 2024-08-30 G. Contursi , P. de Laverny , A. Recio-Blanco , M. Molero , E. Spitoni , F. Matteucci , S. Cristallo

The primary objective of this study is to accurately determine the abundances of Cu, Sr, Y, Zr, Ba, La, and Ce in selected solar-type stars. This will allow us to establish observational abundance-metallicity and abundance-age relations and…

Solar and Stellar Astrophysics · Physics 2024-07-23 Valentina Sheminova , Martina Baratella , Valentina D'Orazi

We report on the determination of chemical abundances of 38 solar analogues, including 11 objects previously identified as super metal-rich stars. We have measured the equivalent widths for 34 lines of 7 different chemical elements (Mg, Al,…

Solar and Stellar Astrophysics · Physics 2017-02-08 Ricardo López-Valdivia , Emanuele Bertone , Miguel Chávez

We present detailed abundance results for 9 Galactic bulge stars in Baade's Window, based on HIRES (R=45,000--60,000) spectra taken with the Keck I telescope. The alpha elements show non-uniform enhancements relative to the Solar…

Astrophysics · Physics 2007-05-23 Andrew McWilliam , R. Michael Rich

Our understanding of the chemical evolution of the Galactic bulge requires the determination of abundances in large samples of giant stars and planetary nebulae (PNe). We discuss PNe abundances in the Galactic bulge and compare these…

Astrophysics · Physics 2009-11-13 C. Chiappini , S. Gorny , G. Stasinska , B. Barbuy

For the first time, we present an extensive study of stars with individual non-local thermodynamic equilibrium (NLTE) abundances for 17 chemical elements from Li to Eu in a sample of stars uniformly distributed over the $-2.62 \le$ [Fe/H]…

Interesting chemically peculiar field stars may reflect their stellar evolution history and their possible origin in a different environment from where they are found now, which is one of the most important research fields in Galactic…

Astrophysics of Galaxies · Physics 2020-03-11 Baitian Tang , J. G. Fernandez-Trincado , Chao Liu , Jincheng Yu , Hongliang Yan , Qi Gao , Jianrong Shi , Douglas Geisler

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

(ABRIDGED) We use the 17th data release of the second phase of the Apache Point Observatory Galactic Evolution Experiment (APOGEE-2) to provide a homogenous census of N-rich red giant stars across the Milky Way (MW). We report a total of…

Abundances of Mg, Ca, Sc, Cr, Fe, and Ni are derived for A stars of five nearby open clusters of various ages using high resolution spectroscopy. We point out a correlation between the abundance of Ca and that of Sc, suggesting that the…

Astrophysics · Physics 2007-05-23 A. Hui-Bon-Hoa

NGC 6558 is a bulge globular cluster with a blue horizontal branch (BHB), combined with a metallicity of [Fe/H]~-1.0. It is similar to HP 1 and NGC 6522, which could be among the oldest objects in the Galaxy. Element abundances in these…

Solar and Stellar Astrophysics · Physics 2018-11-28 B. Barbuy , L. Muniz , S. Ortolani , H. Ernandes , B. Dias , I. Saviane , L. Kerber , E. Bica , A. Pérez-Villegas , L. Rossi , E. V. Held

We present a chemical abundance distribution study in 14 $\alpha$, odd-Z, even-Z, light, and Fe-peak elements of approximately 3200 intermediate metallicity giant stars from the APOGEE survey. The main aim of our analysis is to explore the…

Astrophysics of Galaxies · Physics 2016-03-02 Keith Hawkins , Paula Jofre , Thomas Masseron , Gerry Gilmore

We present an abundance analysis based on high dispersion and high signal-to-noise ratio Keck spectra of a very highly microlensed Galactic bulge dwarf, OGLE-2007-BLG-349S, with Teff ~ 5400 K. The amplification at the time the spectra were…

Astrophysics · Physics 2009-11-13 Judith G. Cohen , Wenjin Huang , A. Udalski , Andrew Gould , Jennifer Johnson

We present a first systematic investigation of the iron abundance in very hot (Teff>50,000K) hydrogen-deficient post-AGB stars. Our sample comprises 16 PG1159 stars and four DO white dwarfs. We use recent FUSE observations as well as HST…

Astrophysics · Physics 2009-11-07 S. Miksa , J. L. Deetjen , S. Dreizler , J. W. Kruk , T. Rauch , K. Werner