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

200 papers

There are many candidate sites of the r-process: core-collapse supernovae (including rare magnetorotational core-collapse supernovae), neutron star mergers, and neutron star/black hole mergers. The chemical enrichment of…

Astrophysics of Galaxies · Physics 2018-12-19 Gina E. Duggan , Evan N. Kirby , Serge M. Andrievsky , Sergey A. Korotin

Chemical clocks based on [s-process elements/alpha-elements] ratios are widely used to estimate ages of Galactic stellar populations. However, the [s/alpha] vs. age relations are not universal, varying with metallicity, location in the…

Using the DR12 public release of APOGEE data, we show that thin and thick disk separate very well in the space defined by [$\alpha$/Fe], [Fe/H] and [C/N]. Thick disk giants have both higher [C/N] and higher [$\alpha$/Fe] than do thin disk…

Solar and Stellar Astrophysics · Physics 2015-09-03 T. Masseron , G. Gilmore

There has been a concerted effort in recent years to identify the astrophysical sites of the $r$-process that can operate early in the Galaxy. The discovery of many $r$-process-enhanced (RPE) stars (especially by the $R$-process Alliance…

Solar and Stellar Astrophysics · Physics 2023-08-02 Pallavi Saraf , Carlos Allende Prieto , Thirupathi Sivarani , Avrajit Bandyopadhyay , Timothy C. Beers , A. Susmitha

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…

In preparation for the HERMES chemical tagging survey of about a million Galactic FGK stars, we estimate the number of independent dimensions of the space defined by the stellar chemical element abundances [X/Fe]. [...] We explore…

Solar and Stellar Astrophysics · Physics 2012-03-21 Yuan-Sen Ting , Kenneth C. Freeman , Chiaki Kobayashi , Gayandhi M. De Silva , Joss Bland-Hawthorn

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

Galactic Archeology is a powerful tool for investigating the formation and evolution of the Milky Way. We use this technique to study kinematic groups of F- and G-stars in the solar neighbourhood. From correlations between orbital…

Astrophysics of Galaxies · Physics 2012-03-29 E. Stonkutė , G. Tautvaišienė , B. Nordström , R. Ženovienė

This contribution presents an overview of the evolution of Li abundances in stars of the Galactic thin and thick discs, from the observational point of view. The focus is on Li abundances obtained by recent projects and surveys. To separate…

Solar and Stellar Astrophysics · Physics 2020-06-23 Rodolfo Smiljanic

As stars traverse the Milky Way, their orbits evolve through perturbations that alter their orbital radii. These changes arise from two mechanisms: churning, which modifies angular momentum, and blurring, which induces eccentric orbits…

Astrophysics of Galaxies · Physics 2025-12-18 M. L. L. Dantas , R. Smiljanic , R. S. de Souza , P. B. Tissera , L. Magrini

We analyse a set of very metal-poor stars for which accurate chemical abundances have been obtained as part of the ESO Large Program "First stars" in the light of the Gaia DR2 data. The kinematics and orbital properties of the stars in the…

Astrophysics of Galaxies · Physics 2020-04-29 P. Di Matteo , M. Spite , M. Haywood , P. Bonifacio , A. Gómez , F. Spite , E. Caffau

In this work we present and discuss the observations of the Mn abundances for 247 FGK dwarfs, located in the Galactic disc with metallicity -1<Fe/H]<+0.3. The observed stars belong to the substructures of the Galaxy thick and thin discs,…

Astrophysics of Galaxies · Physics 2015-10-14 T. Mishenina , T. Gorbaneva , M. Pignatari , F. -K. Thielemann , S. A. Korotin

In order to understand the roles of metal flows in galaxy formation and evolution, we analyse our self-consistent cosmological chemo-dynamical simulation of a Milky Way like galaxy during its thin-disc phase. Our simulated galaxy disc…

Astrophysics of Galaxies · Physics 2020-06-03 Fiorenzo Vincenzo , Chiaki Kobayashi

The spatial distribution of elemental abundances in the disc of our Galaxy gives insights both on its assembly process and subsequent evolution, and on the stellar nucleogenesis of the different elements. Gradients can be traced using…

The present sample of nearby bulgelike dwarf stars has kinematics and metallicities characteristic of a probable inner disk or bulge origin. Ages derived by using isochrones give 10-11 Gyr for these stars and metallicities are in the range…

Astrophysics · Physics 2009-11-07 Luciana Pompeia , Beatriz Barbuy , Michel Grenon

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

The heaviest metals found in stars in most ultra-faint dwarf (UFD) galaxies in the Milky Way halo are generally underabundant by an order of magnitude or more when compared with stars in the halo field. Among the heavy elements produced by…

Astrophysics of Galaxies · Physics 2017-01-25 Ian U. Roederer

We used the spectroscopic and astrometric data provided from the GALAH DR2 and Gaia DR2, respectively, for a large sample of stars to investigate the behaviour of the [$\alpha$/Fe] abundances via two procedures, i.e. kinematically and…

Astrophysics of Galaxies · Physics 2019-11-13 S. Karaali , S. Bilir , E. Yaz Gokce , O. Plevne

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

The best way to trace back the history of star formation and mass assembly of the Milky Way disc is by combining chemical compositions, ages and phase-space information for a large number of disc stars. With the advent of large surveys of…

Astrophysics of Galaxies · Physics 2018-08-22 J. Ted Mackereth , Jo Bovy , Ricardo P. Schiavon , SDSS-IV/APOGEE Collaboration