Constraining the supersaturation density equation of state from core-collapse supernova simulations - Excluded volume extension of the baryons

TL;DR

This study investigates how the supersaturation density equation of state affects core-collapse supernova simulations by extending the nuclear EOS with an excluded volume model for baryons, finding minimal impact on supernova dynamics.

Contribution

It introduces an excluded volume extension to the nuclear EOS for supernova simulations, exploring extreme stiff and soft variants at supersaturation densities.

Findings

Supersaturation density EOS has negligible effect on supernova dynamics.

Neutrino signals are unaffected by the EOS modifications.

Impact is mainly from low- and intermediate-density regimes.

Abstract

In this article the role of the supersaturation density equation of state (EOS) is explored in simulations of failed core-collapse supernova explosions. Therefore the nuclear EOS is extended via a one-parameter excluded volume description for baryons, taking into account their finite and increasing volume with increasing density in excess of saturation density. Parameters are selected such that the resulting supernova EOS represent extreme cases, with high pressure variations at supersaturation density which feature extreme stiff and soft EOS variants of the reference case, i.e. without excluded volume corrections. Unlike in the interior of neutron stars with central densities in excess of several times saturation density, central densities of core-collapse supernovae reach only slightly above saturation density. Hence, the impact of the supersaturation density EOS on the supernova dynamics as well as the neutrino signal is found to be negligible. It is mainly determined from the low- and intermediate-density domain, which is left unmodified within this generalized excluded volume approach.