R-process Nucleosynthesis from Three-Dimensional Magnetorotational Core-Collapse Supernovae

TL;DR

This study uses 3D general-relativistic magnetohydrodynamic simulations to explore r-process nucleosynthesis in magnetorotational core-collapse supernovae, revealing the importance of 3D dynamics and magnetic field strength on element production.

Contribution

It demonstrates that 3D effects and magnetic field strength critically influence r-process yields in magnetorotational supernovae, highlighting limitations of axisymmetric models.

Findings

3D dynamics significantly affect nucleosynthesis outcomes.

Kink instability reduces r-process production by a factor of 100.

Unrealistically large magnetic fields are needed for robust r-process in these supernovae.

Abstract

We investigate r-process nucleosynthesis in three-dimensional (3D) general-relativistic magnetohydrodynamic simulations of rapidly rotating strongly magnetized core collapse. The simulations include a microphysical finite-temperature equation of state and a leakage scheme that captures the overall energetics and lepton number exchange due to postbounce neutrino emission and absorption. We track the composition of the ejected material using the nuclear reaction network SkyNet. Our results show that the 3D dynamics of magnetorotational core-collapse supernovae (CCSN) are important for their nucleosynthetic signature. We find that production of r-process material beyond the second peak is reduced by a factor of 100 when the magnetorotational jets produced by the rapidly rotating core undergo a kink instability. Our results indicate that 3D magnetorotationally powered CCSNe are a robust r-process source only if they are obtained by the collapse of cores with unrealistically large precollapse magnetic fields of order $10^{13}$G. Additionally, a comparison simulation that we restrict to axisymmetry, results in overly optimistic r-process production for lower magnetic field strengths.