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Related papers: The s Process: Nuclear Physics, Stellar Models, Ob…

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We suggest that if the astrophysical site for r-process nucleosynthesis in the early Galaxy is confined to a narrow mass range of Type II supernova (SN II) progenitors, with a lower mass limit of Mms = 20 Msun, a unique feature in the…

Astrophysics · Physics 2009-10-31 Takuji Tsujimoto , Toshikazu Shigeyama , Yuzuru Yoshii

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 report the abundances of neutron-capture elements in eight carbon-rich, metal-poor (-2.7=<[Fe/H]=<-1.9) stars observed with the Subaru Telescope High Dispersion Spectrograph. The derived abundance patterns indicate that the…

Astrophysics · Physics 2008-11-26 W. Aoki , S. G. Ryan , J. E. Norris , T. C. Beers , H. Ando

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…

In the past years the observational evidence that s-process elements from Sr to Pb are produced by stars ascending the socalled Asymptotic Giant Branch (or AGB) could not be explained by self-consistent models, forcing researchers to…

Solar and Stellar Astrophysics · Physics 2017-11-09 S. Palmerini , O. Trippella , M. Busso , D. Vescovi , M. Petrelli , A. Zucchini , F. Frondini

We quantify the stellar abundances of neutron-rich r-process nuclei in cosmological zoom-in simulations of a Milky Way-mass galaxy from the Feedback In Realistic Environments project. The galaxy is enriched with r-process elements by binary…

Astrophysics of Galaxies · Physics 2015-06-22 Freeke van de Voort , Eliot Quataert , Philip F. Hopkins , Dusan Keres , Claude-Andre Faucher-Giguere

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 origin of the elements is a fascinating question that scientists have been trying to answer for the last seven decades. The formation of light elements in the primordial universe and heavier elements in astrophysical sources occurs…

Solar and Stellar Astrophysics · Physics 2019-01-30 V. Liccardo , M. Malheiro , M. S. Hussein , B. V. Carlson , T. Frederico

In the course of a systematic exploration of the uncertainties associated to the input micro- and macro-physics in the modeling of the evolution of intermediate mass stars during their Asymptotic Giant Branch (AGB) phase, we focus on the…

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

Primordial nucleosynthesis is considered a success story of the standard big bang (SBB) cosmology. The cosmological and elementary particle physics parameters are believed to be severely constrained by the requirement of correct abundances…

Astrophysics · Physics 2007-05-23 Daksh Lohiya , Shobhit Mahajan , A. Mukherjee , Annu Batra

Neutrinos are produced during stellar evolution by means of thermal and thermonuclear processes. We model the cumulative neutrino flux expected at Earth from all stars in the Milky Way: the Galactic stellar neutrino flux (GS$\nu$F). We…

Solar and Stellar Astrophysics · Physics 2026-01-08 Pablo Martínez-Miravé , Irene Tamborra

We have computed detailed evolution and nucleosynthesis models for super and massive AGB stars over the mass range 6.5-9.0 Msun in divisions of 0.5 Msun with metallicities Z=0.02, 0.008 and 0.004. These calculations, in which we find third…

Solar and Stellar Astrophysics · Physics 2015-06-17 Carolyn L. Doherty , Pilar Gil-Pons , Herbert H. B Lau , John C. Lattanzio , Lionel Siess

Metals -- heavy elements synthesized during various phases of stellar evolution or during supernova explosions -- play a fundamental role in shaping galaxy evolution. In fact, their relative abundances, spatial distribution, and scaling…

Astrophysics of Galaxies · Physics 2025-04-15 Mirko Curti

The evolution and distribution of metals within galaxies are critical for understanding galactic evolution and star formation processes, but the mechanisms responsible for shaping this distribution remain uncertain. In this study, we carry…

Astrophysics of Galaxies · Physics 2025-02-03 Chuhan Zhang , Zefeng Li , Zipeng Hu , Mark R. Krumholz

Rocky asteroids and planets display nucleosynthetic isotope variations that are attributed to the heterogeneous distribution of stardust from different stellar sources in the solar protoplanetary disk. Here we report new high precision…

Earth and Planetary Astrophysics · Physics 2020-02-07 Mattias Ek , Alison C. Hunt , Maria Lugaro , Maria Schönbächler

The considerable scatter of the s- and r-process elements observed in low-metallicity stars, compared to the small star to star scatter observed for the alpha elements, is an open question for the chemical evolution studies. We have…

Astrophysics · Physics 2007-05-23 G. Cescutti

The recent parameterisation by the GSP-spec module of Gaia/RVS spectra has produced an homogeneous catalogue of about 174,000 AGB stars. Among the 13 chemical elements presented in this catalogue, the abundance of 2 of them (Ce and Nd) have…

Solar and Stellar Astrophysics · Physics 2024-01-02 G. Contursi , P. de Laverny , A. Recio-Blanco , P. A. Palicio , C. Abia

We have calculated the stellar $\beta$-decay rate of the important s-process branching point ${}^{134}$Cs based on the state of the art shell model calculations. At typical $s$-process temperatures ($T\sim$ 0.2-0.3 GK), our new rate is one…

We have investigated a highly energetic H-ingestion event during shell He burning leading to H-burning luminosities of $\log(L_\mathrm{H}/\mathrm{\Lsun}) \sim 13$ in a $45 \Msun$ Pop III massive stellar model. In order to track the…

Solar and Stellar Astrophysics · Physics 2017-12-27 O. Clarkson , F. Herwig , M. Pignatari

The production of the neutron-capture isotopes beyond iron that we observe today in the solar system is the result of the combined contribution of the r-process, the s- process and possibly the i-process. Low-mass AGB (2 < M/Msun < 3) and…