Related papers: s-Process Nucleosynthesis in Carbon Stars
Models of primordial and hyper-metal-poor stars with masses similar to the Sun experience an ingestion of protons into the hot core during the core helium flash phase at the end of their red giant branch evolution. This produces a…
We investigate the enrichment in elements produced by the slow neutron-capture process ($s$-process) in the globular clusters M4 (NGC 6121) and M22 (NGC 6656). Stars in M4 have homogeneous abundances of Fe and neutron-capture elements, but…
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…
Low-mass stars are element factories that efficiently release their products in the final stages of their evolution by means of stellar winds. Since they are large in number, they contribute significantly to the cosmic matter cycle. To…
Many nucleosynthesis and mixing processes of low-mass stars as they evolve from the Main Sequence to the thermal-pulse Asymptotic Giant Branch phase (TP-AGB) are well understood (although of course important physics components, e.g.…
Among presolar materials recovered in meteorites, abundant SiC and Al$_{2}$O$_{3}$ grains of AGB origins were found. They showed records of C, N, O, $^{26}$Al and s-element isotopic ratios that proved invaluable in constraining the…
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…
Low and intermediate mass stars with super solar metallicities comprise a known portion of the universe. Yet yields for asymptotic giant branch (AGB) stars with metallicities greater than $Z=0.04$ do not exist in the literature. This…
We examine nucleosynthesis in the electron capture supernovae of progenitor AGB stars with an O-Ne-Mg core (with the initial stellar mass of 8.8 M_\odot). Thermodynamic trajectories for the first 810 ms after core bounce are taken from a…
Low mass Asymptotic Giant Branch stars are among the most important polluters of the interstellar medium. In their interiors, the main component (A>90) of the slow neutron capture process (the s-process) is synthesized, the most important…
This paper is part of a larger project in which we systematically study the chemical abundances of Galactic and extragalactic post-asymptotic giant branch (post-AGB) stars. Lead (Pb) is the final product of the s-process nucleosynthesis and…
Barium stars are s-process enriched giants. They owe their chemical peculiarities to a past mass transfer phase. During which they were polluted by their binary companion, which at the time was an AGB star, but is now an extinct white…
The chemical abundances of elements such as barium and the lanthanides are essential to understand the nucleosynthesis of heavy elements in the early Universe as well as the contribution of different neutron capture processes (for example…
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…
Neutron-capture elements, those with Z > 35, are the least well-understood in terms of nucleosynthesis and formation environments. The rapid neutron-capture, or r-process, elements are formed in the environments and/or remnants of massive…
Many observed CEMP stars are found in binary systems and show enhanced abundances of $s$-elements. The origin of the chemical abundances of these CEMP-$s$ stars is believed to be accretion in the past of enriched material from a primary…
Context: This paper is part of a larger project in which we study the chemical abundances of extra-galactic post-AGB stars with the ultimate goal of improving our knowledge of the poorly understood AGB third dredge-up mixing processes and…
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…
Detailed chemical composition studies of stars with enhanced abundances of neutron-capture elements can provide observational constraints for neutron-capture nucleosynthesis studies and clues for understanding their contribution to the…
Neutron captures produce the vast majority of abundances of elements heavier than iron in the Universe. Beyond the classical slow (s) and rapid (r) processes, there is observational evidence for neutron-capture processes that operate at…