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Related papers: The AMBRE Project: r-process elements in the Milky…

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In a recent study, based on homogeneous barium abundance measurements in open clusters, a trend of increasing [Ba/Fe] ratios for decreasing cluster age was reported. We present here further abundance determinations, relative to four other…

Solar and Stellar Astrophysics · Physics 2015-05-28 E. Maiorca , S. Randich , M. Busso , L. Magrini , S. Palmerini

The role of compact binary mergers as the main production site of r-process elements is investigated by combining stellar abundances of Eu observed in the Milky Way, galactic chemical evolution (GCE) simulations, binary population synthesis…

[ABRIDGED] The purpose of this work is to evaluate how several elements produced by different nucleosynthesis processes behave with stellar age and provide empirical relations to derive stellar ages from chemical abundances. We derive…

Extensive progress has been recently made into our understanding of heavy element production via the $r$-process in the Universe, specifically with the first observed neutron star binary merger (NSBM) event associated with the gravitational…

We present detailed chemical abundances of three new bright (V ~ 11), extremely metal-poor ([Fe/H] ~ -3.0), r-process-enhanced halo red giants based on high-resolution, high-S/N Magellan/MIKE spectra. We measured abundances for 20-25…

Using multi-element abundances from the SDSS APOGEE survey, we investigate the origin of abundance variations in Milky Way (MW) disk stars on the "high-$\alpha$ plateau," with $-0.5\leq\rm{[Mg/H]}\leq-0.1$ and…

Astrophysics of Galaxies · Physics 2025-09-25 Tawny Sit , David H. Weinberg , Emily J. Griffith

Chemical tagging is a central pursuit of galactic archaeology, but requires sufficiently discriminative abundances to uniquely identify sites of star formation. This task is complicated by intrinsic scatter among conatal stars,…

Astrophysics of Galaxies · Physics 2025-04-28 Jennifer Mead , Rebeca De La Garza , Melissa Ness

Based on the high resolution and high signal-to-noise spectra, we derived the chemical abundances of 20 elements for 20 barium (Ba-) stars. For the first time, the detailed abundances of four sample stars, namely HD 92482, HD 150430, HD…

Solar and Stellar Astrophysics · Physics 2024-10-18 Guochao Yang , Jingkun Zhao , Yanchun Liang , Monique Spite , Francois Spite , Jianrong Shi , Shuai Liu , Nian Liu , Wenyuan Cui , Gang Zhao

AIMS: The aim of this study is to investigate the origin and evolution of Sc, V, Mn, and Co for a homogeneous and statistically significant sample of stars probing the different populations of the Milky Way, in particular the thin and thick…

Astrophysics of Galaxies · Physics 2015-04-22 Chiara Battistini , Thomas Bensby

We present chemical abundances of 57 metal-poor stars that are likely constituents of the outer stellar halo in the Milky Way. Almost all of the sample stars have an orbit reaching a maximum vertical distance (Z_max) of >5 kpc above and…

Astrophysics of Galaxies · Physics 2015-05-14 M. Ishigaki , M. Chiba , W. Aoki

We report the discovery of nine metal-poor stars with high levels of r-process enhancement (+0.81<[Eu/Fe]<+1.13), including six subgiants and three stars on the red horizontal branch. We also analyze four previously-known r-process-enhanced…

Solar and Stellar Astrophysics · Physics 2015-06-22 Ian U. Roederer , John J. Cowan , George W. Preston , Stephen A. Shectman , Chris Sneden , Ian B. Thompson

We analyse the chemical properties of a set of solar vicinity stars, and show that the small dispersion in abundances of \alpha-elements at all ages provides evidence that the SFH has been uniform throughout the thick disk. In the context…

Astrophysics of Galaxies · Physics 2015-04-13 M. Haywood , P. Di Matteo , O. Snaith , M. Lehnert

We develop a chemical evolution model in order to study the star formation history of the Milky Way. Our model assumes that the Milky Way is formed from a closed box-like system in the inner regions, while the outer parts of the disc…

Astrophysics of Galaxies · Physics 2015-06-10 O. Snaith , M. Haywood , P. Di Matteo , M. D. Lehnert , F. Combes , D. Katz , A. Gómez

One of the Milky Way's characteristic features is a strongly bimodal distribution of $\alpha$-process elements, such as Mg, at fixed [Fe/H] in stellar abundances. We examine patterns in [Mg/Fe] versus [Fe/H] in FIRE-2 simulations of Milky…

Astrophysics of Galaxies · Physics 2026-01-07 Megan Barry , Andrew Wetzel , Sarah Loebman , Jeremy Bailin , Hanna Parul

A large star-to-star variation in the abundances of r-process elements, as seen in the [Eu/Fe] ratio for Galactic halo stars, is a prominent feature that is distinguishable from other heavy elements. It is, in part, caused by the presence…

Astrophysics of Galaxies · Physics 2020-02-12 Takuji Tsujimoto , Nobuya Nishimura , Koutarou Kyutoku

The chemical abundances of metal-poor stars provide important clues to explore stellar formation history and set significant constraints on models of the r-process. In this work, we find that the abundance patterns of the light and iron…

Solar and Stellar Astrophysics · Physics 2014-07-21 Hongjie Li , Wenjuan Ma , Wenyuan Cui , Bo Zhang

Many works have attempted to investigate the astrophysical origin of the neutron-capture elements in the metalpoor star HD 140283. However, no definite conclusions have been drawn. In this work, using the abundancedecomposed approach, we…

Solar and Stellar Astrophysics · Physics 2015-11-17 Ping Niu , Wenyuan Cui , Bo Zhang

We model the abundance gradients in the disk of the Milky Way for several chemical elements (O, Mg, Si, S, Ca, Sc, Ti, Co, V, Fe, Ni, Zn, Cu, Mn, Cr, Ba, La and Eu), and compare our results with the most recent and homogeneous observational…

Astrophysics · Physics 2009-11-11 G. Cescutti , F. Matteucci , P. Francois , C. Chiappini

We present a detailed chemical-abundance analysis of a highly $r$-process enhanced (RPE) star, 2MASS J00512646-1053170, using high-resolution spectroscopic observations with $Hubble\ Space\ Telescope$/STIS in the UV and Magellan/MIKE in the…

The abundance of elements synthesized by the rapid neutron-capture process (r-process elements) of extremely metal-poor (EMP) stars in the Local Group galaxies gives us clues to clarify the early evolutionary history of the Milky Way halo.…

Astrophysics of Galaxies · Physics 2017-01-18 Yutaka Hirai , Yuhri Ishimaru , Takayuki R. Saitoh , Michiko S. Fujii , Jun Hidaka , Toshitaka Kajino
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