Related papers: Early Solar System $r$-process Abundances Limit Co…
One of the open questions following the discovery of GW170817 is whether neutron star mergers are the only astrophysical sites capable of producing $r$-process elements. Simulations have shown that 0.01-0.1M$_\odot$ of $r$-process material…
The origin of the heavy elements in the Universe is not fully determined. Neutron star-black hole (NSBH) and {binary neutron star} (BNS) mergers may both produce heavy elements via rapid neutron-capture (r-process). We use the recent…
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…
Collapsar disks have been proposed to be rich factories of heavy elements, but the major question of whether their outflows are neutron-rich, and could therefore represent significant sites of the rapid neutron-capture (r-) process, or…
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…
A long-standing scientific puzzle has been to explain the origin of the heaviest elements in the Universe and, more particularly, the production of the elements heavier than iron up to uranium. The rapid neutron capture process (or…
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…
Several circumstantial arguments point to the formation of the third r-process peak at A about 190, near platinum, in stars of mass of about 8-10 solar masses: 1) The delayed production of europium with respect to iron imposes a time scale…
Comparing Galactic chemical evolution models to the observed elemental abundances in the Milky Way, we show that neutron star mergers can be a leading r-process site only if at low metallicities such mergers have very short delay times and…
It is argued that the abundances of r-process related elements in stars with -3<[Fe/H]<-1 can be explained by the contributions of three sources. The sources are: the first generations of very massive (>100 solar masses) stars that are…
Abundance observations indicate the presence of rapid-neutron capture (i.e., r-process) elements in old Galactic halo and globular cluster stars. These observations provide insight into the nature of the earliest generations of stars in the…
The astrophysical production site of the heaviest elements in the universe remains a mystery. Incorporating heavy element signatures of metal-poor, $r$-process enhanced stars into theoretical studies of $r$-process production can offer…
A brief overview of the r-process is given with an emphasis on the observational implications for this process. The conditions required for the major production of the heavy r-process elements (r-elements) with mass numbers A >130 are…
We examine r-process nucleosynthesis in the neutrino-driven wind from the thick accretion disk (or "torus") around a black hole. Such systems are expected as emnants of binary neutron star or neutron star -- black hole mergers. We consider…
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…
An overview of the sources for heavy elements in the early Galaxy is given. It is shown that observations of abundances in metal-poor stars can be used along with a basic understanding of stellar models to guide the search for the source of…
We examine magnetorotationally driven supernovae as sources of $r$-process elements in the early Galaxy. On the basis of thermodynamic histories of tracer particles from a three-dimensional magnetohydrodynamical core-collapse supernova…
The rapid neutron-capture process or r-process is thought to produce the majority of the heavy elements (Z > 30) in extremely metal-poor stars. The same process is also responsible for a significant fraction of the heavy elements in the…
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 consider hot accretion disk outflows from black hole - neutron star mergers in the context of the nucleosynthesis they produce. We begin with a three dimensional numerical model of a black hole - neutron star merger and calculate the…