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

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We search for the existence of chemically-distinct stellar components in the solar neighbourhood using published data. Extending earlier work, we show that when the abundances of Fe, alpha elements, and the r-process element Eu are…

Astrophysics of Galaxies · Physics 2015-05-19 Julio F. Navarro , Mario G. Abadi , Kim A. Venn , Kenneth C. Freeman , Borja Anguiano

Understanding the history and the evolution of the Milky Way disc is one of the main goals of modern astrophysics. We study the velocity dispersion behaviour of Galactic disc stars as a function of the [Mg/Fe] ratio, which can be used as a…

Important insights into the formation and evolution of the Galactic disc(s) are contained in the chemical compositions of stars. We analysed high-resolution and high signal to noise HARPS spectra of 79 solar twin stars in order to obtain…

We investigate, using the Gaia-ESO Survey internal Data-Release 2, the properties of the double sequence of the Milky Way discs (defined chemically as the high-alpha and low-alpha populations), and discuss their compatibility with discs…

Chemical abundances are an essential tool in untangling the Milky Way's enrichment history. However, the evolution of the interstellar medium abundance gradient with cosmic time is lost as a result of radial mixing processes. For the first…

Some of the heavy elements, such as gold and europium (Eu), are almost exclusively formed by the rapid neutron capture process (r-process). However, it is still unclear which astrophysical site between core-collapse supernovae and neutron…

We analyze data from several studies of metal-poor stars in the Milky Way, focusing on both strong (Eu) and weak (Sr) $r$-process elements. Because these elements were injected in an explosion, we calculate the mass swept up when the blast…

High Energy Astrophysical Phenomena · Physics 2018-09-12 Phillip Macias , Enrico Ramirez-Ruiz

We investigate the chemical enrichment of r-process elements in the early evolutionary stages of the Milky Way halo within the framework of hierarchical galaxy formation using a semi-analytic merger tree. In this paper, we focus on heavy…

Astrophysics of Galaxies · Physics 2014-03-05 Yutaka Komiya , Shimako Yamada , Takuma Suda , Masayuki Y. Fujimoto

Probing the origin of r-process elements in the universe represents a multi-disciplinary challenge. We review the observational evidence that probe the properties of r-process sites, and address them using galactic chemical evolution…

We present the results of our investigation of three samples kinematically representative of the thin and thick disks and the Hercules stream using the catalogue of Soubiran & Girard (2005). We have observed abundance trends and age…

Astrophysics · Physics 2009-07-10 Pascal Girard , Caroline Soubiran

Theories of thick disk formation can be differentiated by measurements of stellar elemental abundances. We have undertaken a study of metal-poor stars selected from the RAVE spectroscopic survey of bright stars to establish whether or not…

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…

The aim of this paper is to characterise the abundance patterns of five iron-peak elements (Mn, Fe, Ni, Cu, and Zn) for which the stellar origin and chemical evolution are still debated. We automatically derived iron peak (Mn, Fe, Ni, Cu,…

Solar and Stellar Astrophysics · Physics 2017-10-10 Š. Mikolaitis , P. de Laverny , A. Recio-Blanco , V. Hill , C. C. Worley , M. de Pascale

Our sample of cool dwarf stars from previous papers is extended in this study including 15 moderately metal-deficient stars. The samples of halo and thick disk stars have overlapping metallicities with [Fe/H] in the region from -0.9 to…

Astrophysics · Physics 2009-11-07 L. Mashonkina , T. Gehren , C. Travaglio , T. Borkova

The physical processes driving chemical evolution in the Milky Way can be probed using the distribution of abundances in low-mass FGK type stars in space phase at different times. During their final stages of evolution stars experience…

Solar and Stellar Astrophysics · Physics 2020-01-15 Paula Jofre , Holly Jackson , Marcelo Tucci Maia

We investigate the production sites and the enrichment history of $r$-process elements in the Galaxy, as traced by the [Eu/Fe] ratio, using the high resolution, cosmological zoom-in simulation `Eris'. At $z=0$, Eris represents a close…

Astrophysics of Galaxies · Physics 2015-07-15 Sijing Shen , Ryan Cooke , Enrico Ramirez-Ruiz , Piero Madau , Lucio Mayer , Javiera Guedes

Recent studies of elemental abundances in the Galactic halo and in the Galactic disk have underscored the possibility to kinematically separate different Galactic subcomponents. Correlations between the galactocentric rotation velocity and…

Astrophysics · Physics 2007-05-23 Andreas Koch , E. K. Grebel

The atmospheric parameters and abundances of Mg, Si, Ca, and Ti have been determined for 20 stars using the Gaia DR2 parallaxes, high-resolution spectra, and the non-local thermodynamic equilibrium (non-LTE) line formation modeling. A…

Solar and Stellar Astrophysics · Physics 2019-09-04 Lyudmila Mashonkina , Maria Neretina , Tatyana Sitnova , Yuri Pakhomov

The $([\alpha/{\rm Fe}],[{\rm Fe/H}])$ distribution of Milky Way stars shows at least two distinct sequences, which have traditionally been associated with the thin and thick disc components. The abundance distribution varies systematically…

Astrophysics of Galaxies · Physics 2021-08-04 Sanjib Sharma , Michael R. Hayden , Joss Bland-Hawthorn

Based on a simple, but fairly successful, model of the chemical evolution of the Milky Way disk, we study the evolution of the abundances of the elements He, C, N, O, Ne, Mg, Al, Si, S, Ar and Fe. We use metallicity dependent yields for…

Astrophysics · Physics 2007-05-23 J. L. Hou , N. Prantzos , S. Boissier