Nuclear Statistical Equilibrium Equation of State for Core Collapse

TL;DR

This paper develops an extensive nuclear statistical equilibrium equation of state for supernova matter, incorporating realistic nuclear data and models, and provides results suitable for supernova simulations with detailed comparisons to existing models.

Contribution

It introduces a comprehensive EOS model based on realistic nuclear data, extending previous models with improved cluster functional definitions and medium modifications.

Findings

The model covers a wide range of densities, temperatures, and proton fractions.

Results are compatible with supernova simulation requirements and available in the CompOSE database.

Differences between models are mainly due to cluster functional hypotheses.

Abstract

Extensive calculations of properties of supernova matter are presented, using the extended Nuclear Statistical Equilibrium model of PRC92 055803 (2015) based on a statistical distribution of Wigner-Seitz cells modeled using realistic nuclear mass and level density tables, complemented with a non-relativistic Skyrme functional for unbound particles and beyond drip-line nuclei. Both thermodynamic quantities and matter composition are examined as a function of baryonic density, temperature, and proton fraction, within a large domain adapted for applications in supernova simulations. The results are also provided in the form of a table, with grid mesh and format compatible with the CompOSE platform [http://compose.obspm.fr/] for direct use in supernova simulations. Detailed comparisons are also presented with other existing databases, all based on relativistic mean-field functionals, and the differences between the different models are outlined. We show that the strongest impact on the predictions is due to the different hypotheses used to define the cluster functional and its modifications due to the presence of a nuclear medium.