Gravitational Waves from a Core g-Mode in Supernovae as Probes of the High-Density Equation of State

TL;DR

This paper demonstrates that gravitational waves from core g-modes in supernovae can reveal details about the high-density equation of state, with simulations showing mode frequencies sensitive to the EoS.

Contribution

It introduces a novel method to probe the high-density EoS using gravitational-wave signals from supernova core g-modes in relativistic simulations.

Findings

Mode frequency ranges from 200 to 800 Hz and decreases over time.

Mode characteristics are highly sensitive to the EoS, especially the sound speed around twice saturation density.

Distinctive gravitational-wave features can distinguish between quark-hadron and purely hadronic EoS.

Abstract

Using relativistic supernova simulations of massive progenitor stars with a quark-hadron equation of state (EoS) and a purely hadronic EoS, we identify a distinctive feature in the gravitational-wave signal that originates from a buoyancy-driven mode (g-mode) below the proto-neutron star convection zone. The mode frequency lies in the range $200\lesssim f\lesssim 800\,\text{Hz}$ and decreases with time. As the mode lives in the core of the proto-neutron star, its frequency and power are highly sensitive to the EoS, in particular the sound speed around twice saturation density.