Related papers: Origin of the p-Nuclei in Explosive Nucleosynthesi…
Most gamma-ray bursts are made during the deaths of massive stars. Here the environmental circumstances, stellar evolutionary paths, and explosion physics that might produce the bursts are reviewed. Neither of the two leading models -…
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…
Young, fast-rotating neutron stars are promising candidate sources for the production of ultrahigh energy cosmic rays (UHECRs). The interest in this model has recently been boosted by the latest chemical composition measurements of cosmic…
We investigated r-process nucleosynthesis in magneto-rotational supernovae, based on a new explosion mechanism induced by the magneto-rotational instability. A series of axisymmetric magneto-hydrodynamical simulations with detailed…
We discuss the possibility whether superheavy elements can be produced in Nature by the astrophysical rapid neutron capture process. To this end we have performed fully dynamical network r-process calculations assuming an environment with…
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…
Formation and decay of rod-like and slab-like nuclei, as may be encountered in the outer parts of neutron stars, are examined within a zero-temperature stability analysis with respect to perturbations inducing fission and proton clustering.…
Robust generation of gamma-ray bursts (GRBs) implies the formation of outflows with very low baryon loads and highly relativistic velocities, but more baryon-rich, slower outflows are also likely to occur in most GRB central engine…
The r-process involves neutron-rich nuclei far off stability for which no experimental cross sections are known. Therefore, one has to rely on theory which might be prone to considerable uncertainties far off stability. To investigate the…
The heaviest chemical elements are naturally produced by the rapid neutron-capture process (r-process) during neutron star mergers or supernovae. The r-process production of elements heavier than uranium (transuranic nuclei) is poorly…
Neutron-induced reactions on unstable isotopes play a key role in the nucleosynthesis $i$--, $r$--, $p$--, $rp$-- and $\nu p$--processes occurring in astrophysical scenarios. While direct cross section measurements are possible for…
Although the rapid neutron-capture process, or r-process, is fundamentally important for explaining the origin of approximately half of the stable nuclei with A > 60, the astrophysical site of this process has not been identified yet. Here…
It has been recently proposed that the shocked surface layers of exploding O-Ne-Mg cores provide the conditions for r-process nucleosynthesis, because their rapid expansion and high entropies enable heavy r-process isotopes to form even in…
We review the characteristics of nucleosynthesis in 'Hypernovae', i.e., supernovae with very large explosion energies ($ \gsim 10^{52} $ ergs). The hypernova yields compared to those of ordinary core-collapse supernovae show the following…
Recent studies suggest that binary neutron star (NS-NS) mergers robustly produce the heavy r-process nuclei above the atomic mass number A ~ 130 because of their ejecta consisting of almost pure neutrons (electron fraction of Y_e < 0.1).…
Our understanding of the origin of heavy elements beyond iron relies on the rapid neutron capture process (r-process), which accounts for roughly half of their cosmic abundance. However, the extreme neutron-rich conditions required for the…
Preliminary results of a new set of stellar evolution and nucleosynthesis calculations for massive stars are presented. These results were obtained with an extended reaction network up to Bi. The discussion focuses on the importance of…
In this talk I discuss properties of hot stellar matter at sub-nuclear densities which is formed in supernova explosions. I emphasize that thermodynamic conditions there are rather similar to those created in the laboratory by…
Mathematical model of heavy and superheavy nuclei production in intensive pulsed neutron fluxes of explosive process is developed. The pulse character of the process allows dividing it in time into two stages: very short rapid process of…
We have studied the sensitivity of s-process nucleosynthesis in massive stars to +/- 2 sigma variations in the rates of the triple alpha and 12C(a,g)16O reactions. We simulated the evolution of massive stars from H-burning through Fe-core…