On Variations Of Pre-Supernova Model Properties

TL;DR

This study investigates how variations in nuclear reaction networks and mass resolution affect the properties of 15-30 solar mass pre-supernova stellar models, highlighting key factors influencing model convergence and structural predictions.

Contribution

It provides a detailed quantitative analysis of how nuclear network size and mass resolution impact pre-supernova model properties, informing best practices for stellar modeling.

Findings

Mass resolution impacts early stellar evolution more than isotope number.

Isotope number significantly influences neon, oxygen, and silicon burning variations.

A minimum mass resolution of 0.01 solar masses is needed for helium core mass convergence.

Abstract

We explore the variation in single star 15-30 $\rm{M}_{\odot}$, non-rotating, solar metallicity, pre-supernova MESA models due to changes in the number of isotopes in a fully-coupled nuclear reaction network and adjustments in the mass resolution. Within this two-dimensional plane we quantitatively detail the range of core masses at various stages of evolution, mass locations of the main nuclear burning shells, electron fraction profiles, mass fraction profiles, burning lifetimes, stellar lifetimes, and compactness parameter at core-collapse for models with and without mass loss. Up to carbon burning we generally find mass resolution has a larger impact on the variations than the number of isotopes, while the number of isotopes plays a more significant role in determining the span of the variations for neon, oxygen and silicon burning. Choice of mass resolution dominates the variations in the structure of the intermediate convection zone and secondary convection zone during core and shell hydrogen burning respectively, where we find a minimum mass resolution of $\approx$ 0.01 $\rm{M}_{\odot}$ is necessary to achieve convergence in the helium core mass at the $\approx$5% level. On the other hand, at the onset of core-collapse we find $\approx$30% variations in the central electron fraction and mass locations of the main nuclear burning shells, a minimum of $\approx$127 isotopes is needed to attain convergence of these values at the $\approx$10% level.