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Related papers: What we do and do not know about the s-process

200 papers

High dispersion near-infrared spectra have been taken of seven highly-evolved, variable, intermediate-mass (4-6 Msun) AGB stars in the LMC and SMC in order to look for C, N and O variations that are expected to arise from third dredge-up…

Astrophysics · Physics 2009-11-13 J. A. McSaveney , P. R. Wood , M. Scholz , J. C. Lattanzio , K. H. Hinkle

Light and intermediate nuclei as well as s-process elements have been detected in presolar grains and in evolved red giants. The abundances of some of these nuclei cannot be accounted for by canonical stellar models and require…

Astrophysics of Galaxies · Physics 2010-12-14 M. Busso , E. Maiorca , L. Magrini , S. Randich , S. Palmerini , S. Cristallo

The abundances of the slow neutron-capture (s-) process elements observed in barium stars can be explained by considering mass transfer in a binary system from an asymptotic giant branch (AGB) star onto a smaller mass and less evolved…

Solar and Stellar Astrophysics · Physics 2023-11-17 Partha Pratim Goswami , Aruna Goswami

The Carbon-Nitrogen-Oxygen (CNO) cycle is fundamental to the process of hydrogen burning in stars, serving as a pivotal mechanism. At its core, the primary reaction involves the radiative capture of a proton by $^{12}$C, crucially…

Nuclear Theory · Physics 2024-05-31 Soumya Saha

The discovery of a historical bug in the s-post-process AGB code obtained so far by the Torino group forced us to reconsider the role of primary 16O in the 13C-pocket, produced by the 13C(a, n)16O reaction, as important neutron poison for…

Solar and Stellar Astrophysics · Physics 2015-03-17 R. Gallino , S. Bisterzo , S. Cristallo , O. Straniero

The ejecta of the first probably very massive stars polluted the Big Bang primordial element mix with the first heavier elements. The resulting ultra metal-poor abundance distribution provided the initial conditions for the second stars of…

Astrophysics · Physics 2007-08-30 Falk Herwig

Uncertainties in nucleosynthesis models originating from uncertainties in astrophysical reaction rates were estimated in a Monte Carlo variation procedure. Thousands of rates were simultaneously varied within individual,…

Solar and Stellar Astrophysics · Physics 2018-06-05 T. Rauscher , N. Nishimura , G. Cescutti , R. Hirschi , A. St. J. Murphy

We report a new mechanism for the \textsl{s} in rotating massive metal-poor stars. Our models show that above a critical rotation speed, such stars evolve in a quasi-chemically-homogeneous fashion, which gives rise to a prolific…

Solar and Stellar Astrophysics · Physics 2021-10-28 Projjwal Banerjee , Alexander Heger , Yong-Zhong Qian

Context: It is well known that the so-called s-process is responsible for the production of neutron-rich trans-iron elements, that form the bulk of the "heavy nuclides" (i.e. nuclides more massive than the iron-group nuclei) in the…

Solar and Stellar Astrophysics · Physics 2012-03-21 M. L. Pumo

The main s-process taking place in low mass stars produces about half of the elements heavier than iron. It is therefore very important to determine the importance and impact of nuclear physics uncertainties on this process. We have…

Solar and Stellar Astrophysics · Physics 2018-06-28 G. Cescutti , R. Hirschi , N. Nishimura , J. W. den Hartogh , T. Rauscher , A. St. J. Murphy , S. Cristallo

In this review, we emphasize the interplay between astrophysical observations, modeling, and nuclear physics laboratory experiments. Several important nuclear cross sections for astrophysics have long been identified e.g.…

Nuclear Experiment · Physics 2016-05-26 Alain Coc , Fairouz Hammache , Juergen Kiener

The astrophysical origin of the rapid neutron-capture process (r-process), which produces about half of the elements heavier than iron, remains uncertain. The oldest, most metal-poor stars preserve the chemical signatures of early…

We report Mo isotopic data of 27 new presolar SiC grains, including 12 14N-rich AB (14N/15N>440, AB2) and 15 mainstream (MS) grains, and their correlated Sr and Ba isotope ratios when available. Direct comparison of the data for the MS…

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

Alongside the slow (s) and rapid (r) neutron capture processes, an intermediate neutron capture process (i-process) is thought to exist. It happens when protons are mixed in a convective helium-burning zone, and is referred to as proton…

Solar and Stellar Astrophysics · Physics 2022-11-23 A. Choplin , L. Siess , S. Goriely

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…

We demonstrate that a massive asymptotic giant branch (AGB) star is a good candidate as the main source of short-lived radionuclides in the early solar system. Recent identification of massive (4-8 solar masses) AGB stars in the Galaxy,…

Precise mechanisms by which Active Galactic Nuclei (AGN) receive their gaseous fuel is still a mystery. Here I draw attention to the extra ordinary star formation event that took place in the central ~ 0.5 parsec of our Galaxy. The most…

Astrophysics · Physics 2007-05-23 Sergei Nayakshin

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 study the impact of nuclear input related to weak-decay rates and neutron-capture reactions on predictions for the $s$ process in AGB stars. We provide the first database of surface abundances and stellar yields of the isotopes heavier…

Solar and Stellar Astrophysics · Physics 2025-05-07 B. Szányi , A. Yagüe López , A. I. Karakas , M. Lugaro
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