Explosive nucleosynthesis in core-collapse supernovae

TL;DR

This paper investigates nucleosynthesis in core-collapse supernovae, demonstrating that neutrino-driven winds can produce weak r-process elements, but heavy r-process elements require conditions beyond standard simulations, highlighting the importance of nuclear physics and dynamics.

Contribution

It provides new insights into the conditions needed for r-process element synthesis in supernovae, especially the role of neutrino-driven winds and the impact of nuclear physics inputs.

Findings

Weak r-process elements can be produced in neutrino-driven winds.

Heavy r-process elements require artificially increased wind entropy.

Nuclear physics inputs significantly affect abundance predictions.

Abstract

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 halo stars, at least two components are required: the heavy r-process nuclei (A>130) and the weak r-process which correspond to the lighter heavy nuclei (A<130). In this work, we present nucleosynthesis studies based on trajectories of hydrodynamical simulations for core-collapse supernovae and their subsequent neutrino-driven winds. We show that the weak r-process elements can be produced in neutrino-driven winds and we relate their abundances to the neutrino emission from the nascent neutron star. Based on the latest hydrodynamical simulations, heavy r-process elements cannot be synthesized in the neutrino-driven winds. However, by artificially increasing the wind entropy, elements up to A=195 can be made. In this way one can mimic the general behavior of an ejecta where the r-process occurs. We use this to study the impact of the nuclear physics input (nuclear masses, neutron capture cross sections, and beta-delayed neutron emission) and of the long-time dynamical evolution on the final abundances.