The Gravitational-Wave Signature of Core-Collapse Supernovae

TL;DR

This paper analyzes 3D simulations of core-collapse supernovae to characterize their gravitational-wave signatures, revealing how different physical processes and progenitor properties influence GW emission patterns and energies.

Contribution

It provides detailed predictions of GW signals from supernovae, highlighting the roles of proto-neutron star oscillations, accretion dynamics, and progenitor characteristics, including black-hole formation scenarios.

Findings

Most GW power is carried by f/g-mode and f-mode oscillations.

GW emission correlates with progenitor compactness and varies widely.

Black-hole formation leads to a tapering GW signal without haze features.

Abstract

We calculate the gravitational-wave (GW) signatures of detailed 3D core-collapse supernova simulations spanning a range of massive stars. Most of the simulations are carried out to times late enough to capture more than 95% of the total GW emission. We find that the f/g-mode and f-mode of proto-neutron star oscillations carry away most of the GW power. The f-mode frequency inexorably rises as the proto-neutron star (PNS) core shrinks. We demonstrate that the GW emission is excited mostly by accretion plumes onto the PNS that energize modal oscillations and also high-frequency (``haze") emission correlated with the phase of violent accretion. The duration of the major phase of emission varies with exploding progenitor and there is a strong correlation between the total GW energy radiated and the compactness of the progenitor. Moreover, the total GW emissions vary by as much as three orders of magnitude from star to star. For black-hole formation, the GW signal tapers off slowly and does not manifest the haze seen for the exploding models. For such failed models, we also witness the emergence of a spiral shock motion that modulates the GW emission at a frequency near $\sim$100 Hertz that slowly increases as the stalled shock sinks. We find significant angular anisotropy of both the high- and low-frequency (memory) GW emissions, though the latter have very little power.