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Related papers: An inhomogeneous model for the Galactic halo: a po…

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Abundances of heavier elements (barium and beyond) in many neutron-capture-element-rich halo stars accurately replicate the solar system r-process pattern. However, abundances of lighter neutron-capture elements in these stars are not…

To understand the formation and composition of planetary systems it is important to study their host stars composition since both are formed in the same stellar nebula. In this work we analyze the behaviour of chemical abundances of Cu, Zn,…

The interstellar medium of low-metallicity systems undergoing star formation will show chemical abundance inhomogeneities due to supernova events enriching the medium on a local scale. If the star formation time-scale is shorter than the…

Astrophysics · Physics 2009-11-07 T. Karlsson , B. Gustafsson

We compute the evolution of the abundances of barium and europium in the Milky Way and we compare our results with the observed abundances from the recent UVES Large Program "First Stars". We use a chemical evolution model which already…

Astrophysics · Physics 2007-05-23 G. Cescutti , P. Francois , F. Matteucci , R. Cayrel , M. Spite

New abundances for neutron-capture (n-capture) elements in a large sample of metal-poor giants from the Bond survey are presented. The spectra were acquired with the KPNO 4-m echelle and coude feed spectrographs, and have been analyzed…

Neutron-star mergers were recently confirmed as sites of rapid-neutron-capture (r-process) nucleosynthesis. However, in Galactic chemical evolution models, neutron-star mergers alone cannot reproduce the observed element abundance patterns…

Recent new high-precision abundance data for Galactic halo stars suggest important primary nitrogen production in very metal-poor massive stars. Here, we compute a new model for the chemical evolution of the Milky Way aimed at explaining…

Astrophysics · Physics 2009-11-10 C. Chiappini , F. Matteucci , S. K. Ballero

We investigate stellar elemental abundance patterns at z = 0 in 8 low-mass (M_* = 10^6 - 10^9 M_sun) galaxies in the Feedback in Realistic Environments (FIRE-2) cosmological simulations. Using magnesium (Mg) as a representative…

A stochastic model of the chemical enrichment of metal-poor systems by core-collapse (Type II) supernovae is presented, allowing for large-scale mixing of the enriched material by turbulent motions and cloud collisions in the interstellar…

Astrophysics · Physics 2009-11-11 T. Karlsson

Very old halo stars were previously found to show at least four different abundance 'anomalies', which models of fast rotating massive stars (spinstars) can successfully account for: rise of N/O and C/O, low 12C/13C and a primary-like…

Astrophysics of Galaxies · Physics 2013-05-07 Gabriele Cescutti , Cristina Chiappini , Raphael Hirschi , Georges Meynet , Urs Frischknecht

We propose a new neutron-capture site in early metal-poor and metal-free stars of $\sim 20$--$30 \,\mathrm{M}_\odot$ that results from proton ingestion in the He shell during late stages of the stars' lives. Most of the neutron capture…

Solar and Stellar Astrophysics · Physics 2018-10-12 Projjwal Banerjee , Yong-Zhong Qian , Alexander Heger

One way to constrain the nature of the high-redshift progenitors of the Milky Way is to look at the low-metallicity stellar populations of the different Galactic components today. For example, high-resolution spectroscopy of very metal poor…

Astrophysics of Galaxies · Physics 2015-06-16 Duane M. Lee , Kathryn V. Johnston , Jason Tumlinson , Bodhisattva Sen , Joshua D. Simon

Properties of galaxies vary systematically with the mass of their parent dark matter halos. This basic galaxy - halo connection shows a fair amount of scatter whose origin is not fully understood. Here, we study how differences in the halo…

Astrophysics of Galaxies · Physics 2019-01-29 Robert Feldmann , Claude-André Faucher-Giguère , Dušan Kereš

Carbon-enhanced metal-poor (CEMP) r/s-stars show surface-abundance distributions characteristic of the so-called intermediate neutron capture process (i-process) of nucleosynthesis. We previously showed that the ingestion of protons in the…

Solar and Stellar Astrophysics · Physics 2021-10-27 S. Goriely , L. Siess , A. Choplin

Motivated by the recently improved knowledge on the kinematic and chemical properties of the Galactic metal-poor stars, we present the numerical simulation for the formation of the Galactic stellar halo to interpret the observational…

Astrophysics · Physics 2009-10-31 Kenji Bekki , Masashi Chiba

Spreads in light element abundances among stars (a.k.a. multiple populations) are observed in nearly all globular clusters. One way to map such chemical variations using high-precision photometry is to employ a suitable combination of…

Solar and Stellar Astrophysics · Physics 2018-09-12 Carmela Lardo , Maurizio Salaris , Nate Bastian , Alessio Mucciarelli , Emanuele Dalessandro , Ivan Cabrera-Ziri

The degree of influence that environment and mass have on the stellar populations of early-type galaxies is uncertain. In this paper we present the results of a spectroscopic analysis of the stellar populations of early-type galaxies aimed…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 Craig Harrison , Matthew Colless , Harald Kuntschner , Warrick Couch , Roberto De Propris , Michael Pracy

Context. In recent years, the R-Process Alliance (RPA) has conducted a successful search for stars enhanced in elements produced by the rapid neutron-capture (r-)process. In particular, the RPA has uncovered a number of stars strongly…

We describe the basic features of a Monte Carlo model specifically designed to follow the inhomogenous chemical evolution of the Galactic halo, taking into account the effects of local enrichment and mixing of the halo gas, and with…

Astrophysics · Physics 2007-05-23 C. Travaglio , A. Burkert , D. Galli

We present a comprehensive study of the abundance evolution of the elements from H to U in the Milky Way halo and local disk. We use a consistent chemical evolution model, metallicity dependent isotopic yields from low and intermediate mass…

Astrophysics of Galaxies · Physics 2018-02-21 N. Prantzos , C. Abia , M. Limongi , A. Chieffi , S. Cristallo