An Exploration of the Equation of State Dependence of Core-Collapse Supernova Explosion Outcomes and Signatures

TL;DR

The paper addresses how the nuclear equation of state (EOS) influences core-collapse supernova observables in fully 3D simulations. By directly comparing two EOS implementations, SFHo and DD2, for a 9 $M_\\odot$ progenitor using the Fornax code, it tracks explosion energetics, nucleosynthesis, kicks, gravitational waves, and neutrino signals to late times. The results show that the DD2 EOS yields a weaker, later explosion with lower neutrino luminosities and a more extended protoneutron star, while SFHo produces a faster, more energetic explosion with more neutron-rich ejecta; gravitational-wave and neutrino memory signatures also differ, offering potential EOS diagnostics. The work highlights a clear EOS imprint on multiple CCSN observables and motivates broader multi-progenitor EOS studies to connect nuclear physics to neutron star/black hole birth properties and to interpret future CCSN signals.

Abstract

We explore, using a state-of-the-art simulation code in 3D and to late enough times to witness final observables, the dependence of core-collapse supernova explosions on the nuclear equation of state. Going beyond questions of explodability, we compare final explosion energies, nucleosynthetic yields, recoil kicks, and gravitational-wave and neutrino signatures using the SFHo and DD2 nuclear equations of state (EOS) for a 9-$M_{\odot}$/solar-metallicity progenitor star. The DD2 EOS is stiffer and has a lower effective nucleon mass. The result is a more extended protoneutron star (PNS) and lower central densities. As a consequence, the mean neutrino energies, final explosion energy, and recoil kick speed are lower. Moreover, the evolution of PNS convection differs between the two EOS models in significant ways. This translates in part into interestingly altered neutrino ``light" curves and noticeably altered gravitational-wave signal strengths and frequency characteristics that may be diagnostic. The faster exploding model (SFHo) yields slightly more neutron-rich ejecta and more species with atomic weights between 60 and 90 and a weak r-process. However, this is merely a preliminary study. The next step is a more comprehensive and multi-progenitor set of 3D supernova simulations for various EOSes to late times when the observables have asymptoted. Such a future investigation will have a direct bearing on the neutron star and black hole birth mass functions and the quest towards a fully quantitative theory of supernova observables.