Related papers: The s Process and Beyond
There has been a persistent conundrum in attempts to model the nucleosynthesis of heavy elements by rapid neutron capture (the $r$-process). Although the location of the abundance peaks near nuclear mass numbers 130 and 195 identify an…
The properties of the relative abundances of rapid and slow neutron-capture elements are studied using a catalog containing spectroscopic abundance determinations for 14~elements produced in various nuclear-synthesis processes for 90~open…
We present the science case for characterizing the origin of the heaviest elements on the periodic table, with a focus on those produced by the rapid neutron-capture process (r-process), using the Habitable Worlds Observatory (HWO).…
The astrophysical origin of elements synthesized through the rapid neutron capture process ($r-$process) is a long standing mystery. The hot and dense environments of core-collapse supernovae have been suggested as potential $r-$process…
We examine the r-process in the neutrino-driven proto-neutron-star (PNS) wind of core-collapse supernovae in light of the recent findings of massive neutron stars in binaries as well as of an indication of neutron-richness in the PNS ejecta…
I show that recent observations of r-process abundances in metal-poor stars are difficult to explain if neutron star mergers (NSMs) are the major r-process sources. In contrast, such observations and meteoritic data on Hf182 and I129 in the…
We present a strictly line-by-line differential analysis of a moderately $r$-process-enhanced star ($r$-I: HD~107752) with respect to a strongly $r$-process-enhanced star ($r$-II: CS~31082-0001) to investigate the possible common origin of…
The existence of nuclei with exotic combinations of protons and neutrons provides fundamental information on the forces acting between nucleons. The maximum number of neutrons a given number of protons can bind, neutron drip line1, is only…
A small number of naturally occurring, proton-rich nuclides (the p-nuclei) cannot be made in the s- and r-process. Their origin is not well understood. Massive stars can produce p-nuclei through photodisintegration of pre-existing…
Neutron stars contain matter in one of the densest forms found in the Universe. This feature, together with the unprecedented progress in observational astrophysics, makes such stars superb astrophysical laboratories for a broad range of…
Some nuclear and astrophysical aspects of the r-process are discussed. Particular attention is paid to observations of abundances in metal-poor stars and their implications for the astrophysical site and yield patterns of the r-process. The…
Massive stars are crucial to galactic chemical evolution for elements heavier than iron. Their contribution at early times in the evolution of the Universe, however, is unclear due to poorly constrained nuclear reaction rates. The competing…
We outline a partial historical summary of the steps through which the nucleosynthesis phenomena induced by {\it slow} neutron captures (the {\it s-process}) were clarified, a scientific achievement in which Franz K\"appeler played a major…
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…
We follow the Galactic enrichment of three easily observed light n-capture elements Sr,Y,and Zr.Input stellar yields have been first separated into their respective main and weak s-process,and r-process components.The s-process yields from…
The isotopic abundances of r-process elements in the solar system are traditionally derived as residuals from the subtraction of s-process contributions from total solar abundances. However, the uncertainties in s-process nucleosynthesis --…
Neutron star mergers (NSMs) are one of the most plausible sources of r-process elements in the universe. Therefore NSMs can also be a major source of ultra-heavy elements in cosmic rays. In this paper, we first estimate the contribution of…
We present the results of s-process nucleosynthesis calculations for AGB stars of different metallicities and initial masses. The computations were based on previously published stellar evolutionary models that account for the III dredge up…
There are many candidate sites of the r-process: core-collapse supernovae (including rare magnetorotational core-collapse supernovae), neutron star mergers, and neutron star/black hole mergers. The chemical enrichment of…
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…