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Related papers: R-process and alpha-elements in the Galactic disk:…

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We take advantage of the Gaia-ESO Survey iDR4 bulge data to search for abundance anomalies that could shed light on the composite nature of the Milky Way bulge. The alpha-elements (Mg, Si, and whenever available, Ca) abundances, and their…

We present the chemical abundances of Fe, alpha- and neutron-capture elements in 12 metal-poor Small Magellanic Cloud (SMC) giant stars, observed with the high-resolution spectrographs UVES/VLT and MIKE/Magellan. These stars have [Fe/H]…

We quantify the stellar abundances of neutron-rich r-process nuclei in cosmological zoom-in simulations of a Milky Way-mass galaxy from the Feedback In Realistic Environments project. The galaxy is enriched with r-process elements by binary…

Astrophysics of Galaxies · Physics 2015-06-22 Freeke van de Voort , Eliot Quataert , Philip F. Hopkins , Dusan Keres , Claude-Andre Faucher-Giguere

We have studied 23 long-lived G dwarfs that belong to the thin disk and thick disk stellar populations. Abundances have been derived for 24 elements: O, Na, Mg, Al, Si, Ca, Ti, Sc, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Sr, Y, Zr, Ba, La, Ce, Nd,…

Astrophysics · Physics 2008-11-26 Mary-Margaret Brewer , Bruce W. Carney

The supernova yields of r-process elements are obtained as a function of the mass of their progenitor stars from the abundance patterns of extremely metal-poor stars on the left-side [Ba/Mg]-[Mg/H] boundary with a procedure proposed by…

Astrophysics · Physics 2008-11-26 Zhe Chen , Jiang Zhang , YanPing Chen , WenYuan Cui , Bo Zhang

This paper investigates the peculiar behaviour of the light even (alpha-elements) and odd atomic number elements in red giants in the galactic bulge, both in terms of the chemical evolution of the bulge, and in terms of possible deep-mixing…

Astrophysics · Physics 2009-11-11 A. Lecureur , V. Hill , M. Zoccali , B. Barbuy , A. Gomez , D. Minniti , S. Ortolani , A. Renzini

We present a detailed study of the composition of 20 M giants in the Galactic center with 15 of them confirmed to be in the Nuclear Star Cluster. As a control sample we have also observed 7 M giants in the Milky Way Disk with similar…

In the search of a sample of metal-poor bright giants using Str{\"o}mgren photometry, we serendipitously found a sample of 26 young (ages younger than 1 Gyr) metal-rich giants, some of which have high rotational velocities.We determined the…

The chemical abundances of the metal-poor stars in the stellar stream provide important information for setting constraints on models of neutron-capture processes. The study of these stars could give us a better understanding of r-process…

Solar and Stellar Astrophysics · Physics 2015-06-11 Hongjie Li , Shuai Liang , Wenyuan Cui , Bo Zhang

ABRIDGED: To compare the chemistries of stars in the Milky Way dSph galaxies with stars in the Galaxy, we have compiled a large sample of Galactic stellar abundances from the literature. As found in previous studies, the [alpha/Fe] ratios…

Astrophysics · Physics 2009-11-10 K. A. Venn , M. Irwin , M. D. Shetrone , C. A. Tout , V. Hill , E. Tolstoy

The ultra-faint dwarf galaxy Reticulum II was enriched by a rare and prolific r-process event, such as a neutron star merger. To investigate the nature of this event, we present high-resolution Magellan/MIKE spectroscopy of the brightest…

Solar and Stellar Astrophysics · Physics 2018-04-18 Alexander P. Ji , Anna Frebel

Abundance observations indicate the presence of rapid-neutron capture (i.e., r-process) elements in old Galactic halo and globular cluster stars. Recent observations of the r-process-enriched star BD +17 3248 include new abundance…

Solar and Stellar Astrophysics · Physics 2011-06-07 John J. Cowan , Ian U. Roederer , Christopher Sneden , James E. Lawler

The elements germanium (Ge, Z=32), arsenic (As, Z=33), and selenium (Se, Z=34) span the transition from charged-particle or explosive synthesis of the iron-group elements to neutron-capture synthesis of heavier elements. Among these three…

Solar and Stellar Astrophysics · Physics 2015-06-05 Ian U. Roederer

Using modern published data on velocities and spectroscopic definitions of chemical elements in stellar objects of the Galaxy, we investigated the relationship of chemical composition with the kinematics of different populations. The paper…

Astrophysics of Galaxies · Physics 2020-04-22 V. A. Marsakov , V. V. Koval' , M. L. Gozha

ABRIDGED: METHODS: We have conducted a high-resolution spectroscopic study of 714 F and G dwarf and subgiant stars in the Solar neighbourhood. The star sample has been kinematically selected to trace the Galactic thin and thick disks to…

Astrophysics of Galaxies · Physics 2015-06-17 T. Bensby , S. Feltzing , M. S. Oey

Context. Carbon, nitrogen, and oxygen are the most abundant elements throughout the universe, after hydrogen and helium. Studying these elements in low-metallicity stars can provide crucial information on the chemical composition in the…

We present an analysis of the relative abundance features of a number of chemical elements in the atmospheres of metal-rich ($\rm{[Fe/H]} > -1.0$) Galactic-field RR~Lyrae variable stars and the kinematic characteristics of these stars. We…

Solar and Stellar Astrophysics · Physics 2024-08-07 M. L. Gozha , V. A. Marsakov , V. V. Koval'

We calculate the evolution of heavy element abundances from C to Zn in the solar neighborhood adopting our new nucleosynthesis yields. Our yields are calculated for wide ranges of metallicity (Z=0-Z_\odot) and the explosion energy (normal…

Astrophysics · Physics 2008-11-26 C. Kobayashi , H. Umeda , K. Nomoto , N. Tominaga , T. Ohkubo

We present an empirical s-process abundance distribution derived with explicit knowledge of the r-process component in the low-metallicity globular cluster M22. We have obtained high-resolution, high signal-to-noise spectra for 6 red giants…

Solar and Stellar Astrophysics · Physics 2015-05-30 I. U. Roederer , A. F. Marino , C. Sneden

Most heavy elements beyond the iron peak are synthesized via neutron capture processes. The nature of the astrophysical sites of neutron capture processes is still very unclear. In this work we explore the observational constraints of the…

Solar and Stellar Astrophysics · Physics 2023-09-25 Jianhui Lian , Nicholas Storm , Guillaume Guiglion , Aldo Serenelli , Benoit Cote , Amanda I. Karakas , Nick Boardman , Maria Bergemann