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Elements heavier than hydrogen and helium, collectively termed metals, were created inside stars and dispersed through space at the final stages of stellar evolution. The relative amounts of different isotopes (variants of the same element…

Solar and Stellar Astrophysics · Physics 2025-08-27 Darío González Picos , Ignas Snellen , Sam de Regt

(Abridged) The hierarchical formation scenario for the stellar halo requires the accretion and disruption of dwarf galaxies, yet low-metallicity halo stars are enriched in alpha-elements compared to similar, low-metallicity stars in dwarf…

We study the stellar population history and chemical evolution of the Milky Way (MW) in a hierarchical LCDM model for structure formation. Using a Monte Carlo method based on the semi-analytical EPS formalism, we reconstruct the merger tree…

Astrophysics · Physics 2008-11-26 S. Salvadori , R. Schneider , A. Ferrara

We explore the hypothesis that the classical and ultra-faint dwarf spheroidal satellites of the Milky Way have been the building blocks of the Galactic halo by comparing their [O/Fe] and [Ba/Fe] versus [Fe/H] patterns with the ones observed…

Astrophysics of Galaxies · Physics 2017-05-19 E. Spitoni , F. Vincenzo , F. Matteucci , D. Romano

Context. Recently, for the first time the abundance of P has been measured in disk stars. This provides the opportunity of comparing the observed abundances with predictions from theoretical models. Aims. We aim at predicting the chemical…

Astrophysics of Galaxies · Physics 2015-06-03 G. Cescutti , F. Matteucci , E. Caffau , P. François

The mean alpha-to-iron abundance ratio ([$\alpha$/Fe]) of galaxies is sensitive to the chemical evolution processes at early time, and it is an indicator of star formation timescale ($\tau_{{\rm SF}}$). Although the physical reason remains…

Astrophysics of Galaxies · Physics 2016-10-05 Yiqing Liu , Luis C. Ho , Eric Peng

We reanalyze the chemical composition of the metal-poorest tail of the Galactic halo using highly accurate atmospheric parameters Giribaldi et al. (2021, 2023) and cutting-edge 3D NLTE models Amarsi et al (2018). Most [Mg/Fe] versus [Fe/H]…

Astrophysics of Galaxies · Physics 2025-07-15 Riano E. Giribaldi , Laura Magrini , Martina Rossi , Anish Amarsi , Davide Massari , Donatela Romano

We examine the evolution of Li in the Galactic disk,basing our model on the compilation of Li v.Fe observations in stars of iron abundance ranging between halo values,which give a baseline for the disk Li abundance,and 0.2 dex above…

Astrophysics · Physics 2007-05-23 E , Casuso , J. E. Beckman

We study the evolution of the [Eu/Fe] ratio in the Galactic halo by means of a stochastic chemical evolution model considering merging neutron stars as polluters of europium. We improved our previous stochastic chemical evolution model by…

Astrophysics of Galaxies · Physics 2021-02-10 L. Cavallo , G. Cescutti , F. Matteucci

We study the detailed properties of the radial metallicity gradient in the stellar disk of our Galaxy to constrain its chemical and structural evolution. For this purpose we select and analyze $\sim$ 18,500 disk stars taken from two…

Astrophysics of Galaxies · Physics 2015-06-19 Daisuke Toyouchi , Masashi Chiba

The abundance gradients and the radial gas profile of the Galactic disc are analysed by means of a model for the chemical evolution of galaxies. As one of the major uncertainties in models for galaxy evolution is the star formation (SF)…

Astrophysics · Physics 2007-05-23 L. Portinari , C. Chiosi

We present chemical abundances for the elements carbon, sodium, and fluorine in 15 red giants of the globular cluster M 4, as well as six red giants of the globular cluster $\omega$ Centauri. The chemical abundances were calculated in LTE…

Sulfur is a volatile chemical element that plays an important role in tracing the chemical evolution of galaxies. However, its nucleosynthesis origin and abundance variations are still unclear. The goal of the present article is to…

Astrophysics of Galaxies · Physics 2021-03-31 J. Perdigon , P. de Laverny , A. Recio-Blanco , E. Fernandez-Alvar , P. Santos-Peral , G. Kordopatis , M. A. Alvarez

In the last years, stellar migration in galactic discs has been the subject of several investigations. However, its impact on the chemical evolution of the Milky Way still needs to be fully quantified. In this paper, we aim at imposing some…

Astrophysics of Galaxies · Physics 2015-06-22 E. Spitoni , D. Romano , F. Matteucci , L. Ciotti

We have compiled a sample of 699 stars from the recent literature with detailed chemical abundance information (spanning -4.2 < [Fe/H] < +0.3), and we compute their space velocities and Galactic orbital parameters. We identify members of…

Astrophysics · Physics 2009-11-13 Ian U. Roederer

From exploratory studies and theoretical expectations it is known that simplifying approximations in spectroscopic analysis (LTE, 1D) lead to systematic biases of stellar parameters and abundances. These biases depend strongly on surface…

Solar and Stellar Astrophysics · Physics 2017-10-04 Maria Bergemann , Remo Collet , Ralph Schoenrich , Rene Andrae , Mikhail Kovalev , Gregory Ruchti , Camilla J. Hansen , Zazralt Magic

We develop a hybrid model of galactic chemical evolution that combines a multi-ring computation of chemical enrichment with a prescription for stellar migration and the vertical distribution of stellar populations informed by a cosmological…

The Galactic stellar halo is predicted to have formed at least partially from the tidal disruption of accreted dwarf galaxies. This assembly history should be detectable in the orbital and chemical properties of stars. The H3 Survey is…

In this paper we present a study of chemical abundances in six star-forming regions. Stellar parameters and metallicities are derived using high-resolution, high S/N spectra of weak-line T-Tauri stars in each region. The results show that…

Astrophysics · Physics 2009-11-13 N. C. Santos , C. Melo , D. J. James , J. F. Gameiro , J. Bouvier , J. I. Gomes

A highly homogeneous study of 23 halo field dwarf stars has achieved a Li abundance accuracy of 0.033 dex per star. The work shows that the intrinsic spread of the Li abundances of these stars at a given metallicity is <0.02 dex, and…

Astrophysics · Physics 2007-05-23 Sean G. Ryan