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Related papers: AGB yields and Galactic Chemical Evolution: last u…

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The chemical evolution of neutron capture elements in the Milky Way is still a matter of debate. Although more and more studies investigate their chemical behaviour, there is still a lack of a significant large sample of abundances of a key…

Solar and Stellar Astrophysics · Physics 2024-08-30 G. Contursi , P. de Laverny , A. Recio-Blanco , M. Molero , E. Spitoni , F. Matteucci , S. Cristallo

Several works have found an increase of the abundances of the s-process neutron-capture elements in the youngest Galactic stellar populations, giving important constraints to stellar and Galactic evolution. We aim to trace the abundance…

We present a review of AGB star evolution, with emphasis on the nucleosynthesis occurring in these stars. In particular, we discuss hot and cool bottom burning, observational constraints, and analysis of meteoritic grains. This paper was…

Astrophysics · Physics 2007-05-23 Cheryl Frost , John Lattanzio

We study s-process element abundance ratios in stars by carrying out stellar population synthesis, using a rapid synthetic stellar evolution code which includes an up-to-date treatment of AGB nucleosynthesis and evolution. In contrast to…

Astrophysics · Physics 2007-05-23 A. Bonacic Marinovic , R. G. Izzard , M. Lugaro , O. R. Pols

Context. Barium (Ba) stars are dwarf and giant stars enriched in elements heavier than iron produced by the slow neutron-capture process (s process). They belong to binary systems where the primary star evolved through the asymptotic giant…

Solar and Stellar Astrophysics · Physics 2018-12-12 B. Cseh , M. Lugaro , V. D'Orazi , D. B. de Castro , C. B. Pereira , A. I. Karakas , L. Molnár , E. Plachy , R. Szabó , M. Pignatari , S. Cristallo

We present nucleosynthesis predictions (HeCNOCl) from asymptotic giant branch (AGB) models, with diffusive overshooting from all the convective borders, in the metallicity range Z/4 < Z < 2Zsun. They are compared to recent precise nebular…

Solar and Stellar Astrophysics · Physics 2016-06-15 D. A. Garcia-Hernandez , P. Ventura , G. Delgado-Inglada , F. Dell'Agli , M. Di Criscienzo , A. Yagüe

We analyze the impact on the Galactic nitrogen abundances of using a new set of low and intermediate mass star yields. These yields have a significant yield of primary nitrogen from intermediate mass stars. We use these yields as an input…

Astrophysics · Physics 2009-11-11 Marta Gavilan , Mercedes Molla , James F. Buell

We present new nucleosynthesis yields as functions of the stellar mass, metallicity, and explosion energy (corresponding to normal supernovae and Hypernovae). We apply the results to the chemical evolution of the solar neighborhood. Our new…

Astrophysics · Physics 2011-05-05 Ken'ichi Nomoto , Nozomu Tominaga , Hideyuki Umeda , Chiaki Kobayashi , Keiichi Maeda

The S-type stars are believed to have a C/O-ratio close to unity (within a few percent). They are considered to represent an intermediate evolutionary stage as AGB stars evolve from oxygen-rich M-type stars into carbon stars. As possible…

Solar and Stellar Astrophysics · Physics 2010-11-10 S. Ramstedt , F. L. Schöier , H. Olofsson

We present theoretical evolutionary sequences of intermediate mass stars (M=3-6.5 solar masses) with metallicity Z=0.004. Our goal is to test whether the self-enrichment scenario by massive Asymptotic Giant Branch stars may work for the…

Astrophysics · Physics 2008-01-18 Paolo Ventura Francesca D'Antona

Analytic formulae are presented to construct detailed secular lightcurves of both early asymptotic giant branch (AGB) and thermally pulsing AGB stars. They are based on an extensive grid of evolutionary calculations, performed with an…

Astrophysics · Physics 2007-05-23 J. Wagenhuber , M. A. T. Groenewegen

We present detailed models of low and intermediate-mass asymptotic giant branch (AGB) stars with and without the 18F(a,p)21Ne reaction included in the nuclear network, where the rate for this reaction has been recently experimentally…

Astrophysics · Physics 2009-11-13 Amanda Karakas , Hye Young Lee , Maria Lugaro , Joachim Goerres , Michael Wiescher

The supernova yields of r-process elements are obtained as a function of the mass of their progenitor stars from the abundance patterns of extremely metal-poor stars on the left-side [Ba/Mg]-[Mg/H] boundary with a procedure proposed by…

Astrophysics · Physics 2008-11-26 Zhe Chen , Jiang Zhang , YanPing Chen , WenYuan Cui , Bo Zhang

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

We provide a meta-study of the statistical and individual properties of two volume-complete sets of evolved stars in the Solar Neighbourhood: (1) 852 stars from the Nearby Evolved Stars Survey (NESS), and (2) a partially overlapping set of…

We present and show the features of the FRUITY database, an interactive web-based interface devoted to the nucleosynthesis in AGB stars. We describe the current available set of AGB models (largely expanded with respect to the original one)…

Solar and Stellar Astrophysics · Physics 2016-02-02 S. Cristallo , L. Piersanti , O. Straniero

Bulk meteoritic data show isotopic variability of $slow$-neutron-capture ($s$-process) origin in a several elements heavier than Fe. One peculiar feature is that the lighter $s$-process elements (e.g., Zr and Mo) present larger anomalies…

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…

It is well appreciated that the description of overadiabatic convection affects the structure of the envelopes of luminous asymptotic giant branch (AGB) stars in the phase of ``hot bottom burning '' (HBB). We stress that this important…

Astrophysics · Physics 2009-11-10 Paolo Ventura , Francesca D'Antona

We study the evolution of extremely metal-poor AGB stars, with metallicities down to [Fe/H]=-5, to understand the main evolutionary properties, the efficiency of the processes able to alter their surface chemical composition and to…

Solar and Stellar Astrophysics · Physics 2021-11-03 P. Ventura , F. Dell'Agli , D. Romano , S. Tosi , M. Limongi , A. Chieffi , M. Castellani , M. Tailo , M. Lugaro , E. Marini , A. Yague Lopez