Related papers: r-Process Calculations and Galactic Chemical Evolu…
The $r$-process-enhanced (RPE) stars provide fossil records of the assembly history of the Milky Way and the nucleosynthesis of the heaviest elements. Observations by the $R$-Process Alliance (RPA) and others have confirmed that many RPE…
Core-collapse supernovae are among the most fascinating phenomena in astrophysics and provide a formidable challenge for theoretical investigation. They mark the spectacular end of the lives of massive stars and, in an explosive eruption,…
Advances in our understanding and the modeling of stellar core-collapse and supernova explosions over the past 15 years are reviewed, concentrating on the evolution of hydrodynamical simulations, the description of weak interactions and…
A few rare halo giants in the range [Fe/H] $\simeq -2.9\pm0.3$ exhibit {\it r}-process element abundances that vary as a group by factors up to [$r$/Fe] $\sim80$, relative to those of the iron peak and below. Yet, the astrophysical…
We develop a high-performance analytical model of Galactic Chemical Evolution, which accounts for delay time distributions and lock-up of stellar yields in a thermal-phased ISM. The model is capable of searching, for the first time, through…
Growing interests in the chemical feature of r-process elements among nearby disk stars represented by the [Eu/Fe] vs. [Fe/H] diagram have sprouted since it can assess the origin of r-process elements through the comparison with theoretical…
The production of about half of the heavy elements found in nature is assigned to a specific astrophysical nucleosynthesis process: the rapid neutron capture process (r-process). Although this idea has been postulated more than six decades…
For the origin of heavy r-process elements, different sources have been proposed, e.g., core-collapse supernovae or neutron star mergers. Old metal-poor stars carry the signature of the astrophysical source(s). Among the elements dominantly…
We demonstrate that rapid expansion of the shocked surface layers of an O-Ne-Mg core following its collapse can result in r-process nucleosynthesis. As the supernova shock accelerates through these layers, it makes them expand so rapidly…
We investigate the chemical enrichment of r-process elements in the early evolutionary stages of the Milky Way halo within the framework of hierarchical galaxy formation using a semi-analytic merger tree. In this paper, we focus on heavy…
The origin of rapid neutron capture (r-process) nuclei remains one of the longest standing mysteries in nuclear astrophysics. Core collapse supernovae (SNe) and neutron star binary mergers are likely r-process sites, but little evidence yet…
The discovery of the second highly $r$-process-enhanced, extremely metal-poor star, CS 31082-001 ([Fe/H] $= -2.9$) has provided a powerful new tool for age determination, by virtue of the detection and measurement of the radioactive species…
Meteoritic abundances of r-process elements are analyzed to deduce the history of chemical enrichment by r-process from the beginning of disk formation to the present time in the solar vicinity, by combining the abundance information from…
I compare seven actively studied r-process nucleosynthesis scenarios against observed properties of r-process elements in the early Universe, and conclude that the most likely scenario to contribute to the site of elements below the third…
This paper presents theoretical star formation and chemical enrichment histories for the stellar halo of the Milky Way based on new chemodynamical modeling. The goal of this study is to assess the extent to which metal-poor stars in the…
One of the hottest open issues involving the evolution of r-process elements is fast enrichment in the early Universe. Clear evidence for the chemical enrichment of r-process elements is seen in the stellar abundances of extremely metal…
We report the discovery of nine metal-poor stars with high levels of r-process enhancement (+0.81<[Eu/Fe]<+1.13), including six subgiants and three stars on the red horizontal branch. We also analyze four previously-known r-process-enhanced…
Recent calculations place questions on the ability of supernovae to produce r-process nuclei in the correct amounts. We present results from 3D Newtonian SPH calculations of mergers of equal mass neutron star binaries. We find the amounts…
Metal-poor stars are key for studying the formation and evolution of the Galaxy. Evidence of the early mergers that built up the Galaxy remains in the distributions of abundances, kinematics, and orbital parameters of its stars. Several…
The specific mechanism and astrophysical site for the production of half of the elements heavier than iron via rapid neutron capture (r-process) remains to be found. In order to reproduce the abundances of the solar system and of the old…