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Related papers: Primordial r-process Dispersion in Metal-Poor Glob…

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We present the color distributions of globular cluster (GC) systems for 100 Virgo cluster early-type galaxies observed in the ACS Virgo Cluster Survey. The color distributions of individual GC systems are consistent with continuous trends…

Elements heavier than zinc are synthesized through the (r)apid and (s)low neutron-capture processes. The main site of production of the r-process elements (such as europium) has been debated for nearly 60 years. Initial studies of chemical…

Astrophysics of Galaxies · Physics 2016-09-22 Alexander P. Ji , Anna Frebel , Anirudh Chiti , Joshua D. Simon

Nucleosynthesis of heavy nuclei in metal-poor stars is generally thought to occur via the r-process because the r-process is a primary process that would have operated early in the Galaxy's history. This idea is strongly supported by the…

Solar and Stellar Astrophysics · Physics 2015-06-03 Richard Boyd , Michael Famiano , Bradley Meyer , Yuko Motizuki , Toshitaka Kajino , Ian Roederer

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

In order to get a broader view of the s-process nucleosynthesis we study the abundance distribution of heavy elements of 35 barium stars and 24 CEMP-stars, including nine CEMP-s stars and 15 CEMP-r/s stars. The similar distribution of…

Solar and Stellar Astrophysics · Physics 2013-05-09 Wenyuan Cui , Jianrong Shi , Yuanyuan Geng , Caixia Zhang , Xiaoying Meng , Lang Shao , Bo Zhang

The abundance patterns of metal-poor stars provide us a wealth of chemical information about various stages of the chemical evolution of the Galaxy. In particular, these stars allow us to study the formation and evolution of the elements…

Astrophysics · Physics 2009-04-14 Anna Frebel

We present radial velocities, stellar parameters, and detailed abundances of 39 elements derived from high-resolution spectroscopic observations of red giant stars in the luminous, metal-poor globular cluster NGC 5824. We observe 26 stars…

Solar and Stellar Astrophysics · Physics 2015-12-02 Ian U. Roederer , Mario Mateo , John I. Bailey , Meghin Spencer , Jeffrey D. Crane , Stephen A. Shectman

Recent observations of heavy elements in Globular Clusters reveal intriguing deviations from the standard paradigm of the early galactic nucleosynthesis. If the r-process contamination is a common feature of halo stars, s-process…

Astrophysics of Galaxies · Physics 2015-06-19 Oscar Straniero , Sergio Cristallo , Luciano Piersanti

A brief overview of the r-process is given with an emphasis on the observational implications for this process. The conditions required for the major production of the heavy r-process elements (r-elements) with mass numbers A >130 are…

Astrophysics · Physics 2008-09-18 Yong-Zhong Qian

We study the abundance distributions of a sample of metal-rich barium stars provided by Pereira et al. (2011) to investigate the s- and r-process nucleosynthesis in the metal-rich environment. We compared the theoretical results predicted…

Solar and Stellar Astrophysics · Physics 2014-05-19 W. Y. Cui , B. Zhang , J. R. Shi , G. Zhao , W. J. Wang , P. Niu

Historically,Ge has been considered to be a neutron-capture element. In this case, the r-process abundance of Ge is derived by subtracting the s-process abundance from the total abundance in the Solar system. However, the Ge abundance of…

Solar and Stellar Astrophysics · Physics 2014-09-22 Ping Niu , Weili Liu , Wenyuan Cui , Bo Zhang

Moderately r-process-enriched stars (r-I) are at least four times as common as those that are greatly enriched in r-process elements (r-II), and the abundances in their atmospheres are important tools for obtaining a better understanding of…

Solar and Stellar Astrophysics · Physics 2015-06-19 C. Siqueira-Mello , V. Hill , B. Barbuy , M. Spite , F. Spite , T. C. Beers , E. Caffau , P. Bonifacio , R. Cayrel , P. François , H. Schatz , S. Wanajo

The chemical abundances of elements such as barium and the lanthanides are essential to understand the nucleosynthesis of heavy elements in the early Universe as well as the contribution of different neutron capture processes (for example…

We study turbulent gas diffusion affects on $r$-process abundances in Milky Way stars, by a combination of an analytical approach and a Monte Carlo simulation. Higher $r$-process event rates and faster diffusion, lead to more efficient…

High Energy Astrophysical Phenomena · Physics 2020-06-24 Paz Beniamini , Kenta Hotokezaka

About half of carbon and s-process enhanced metal-poor stars (CEMP-s) show a high r-process enrichment (CEMP-s/r), incompatible with a pure s-process contribution. CEMP-s stars are of low mass (M < 0.9 Msun) and belong to binary systems.…

Solar and Stellar Astrophysics · Physics 2015-03-17 Sara Bisterzo , Roberto Gallino

The rapid neutron-capture process (r-process) is responsible for the creation of roughly half of the elements heavier than iron, including precious metals like silver, gold, and platinum, as well as radioactive elements such as thorium and…

Solar and Stellar Astrophysics · Physics 2025-07-14 Avrajit Bandyopadhyay , Timothy C. Beers

In a brief review of abundances neutron-capture elements (Z > ~30) in metal-poor halo stars, attention is called to their star-to-star scatter, the dominance of r-process synthesis at lowest metallicities, the puzzle of the lighter members…

Astrophysics · Physics 2016-11-03 C. Sneden , J. J. Cowan , J. W. Truran

We present a comprehensive analysis of the detailed chemical abundances for a sample of 11 metal-poor, very metal-poor and extremely metal-poor stars ([Fe/H] = -1.65 to [Fe/H] = -3.0) as part of the HESP-GOMPA (Galactic survey Of Metal Poor…

We present a chemical composition analysis of 36 giants in the nearby mildy metal-poor (<[Fe/H]> = -1.18) "CN-bimodal" globular cluster M4. Confronted with a cluster that has large and variable interstellar extinction across the cluster…

We present a nearly complete rapid neutron-capture process (r-process) chemical inventory of the metal-poor ([Fe/H] = -1.46 +/- 0.10) r-process-enhanced ([Eu/Fe] = +1.32 +/- 0.08) halo star HD 222925. This abundance set is the most complete…