The Gravitational Wave Signature of Core-Collapse Supernovae

TL;DR

This paper reviews gravitational-wave emission processes in core-collapse supernovae, presents new simulation results, and discusses detection prospects with current and future gravitational-wave observatories.

Contribution

It provides updated models and estimates of GW signals from supernovae, including new results on postbounce convective overturn and pulsations, and analyzes detection capabilities.

Findings

Advanced LIGO could detect GWs from supernovae within 3.9 Mpc.

Different supernova explosion mechanisms produce distinguishable GW signatures.

Even initial LIGO might differentiate explosion types through GW detection.

Abstract

We review the ensemble of anticipated gravitational-wave (GW) emission processes in stellar core collapse and postbounce core-collapse supernova evolution. We discuss recent progress in the modeling of these processes and summarize most recent GW signal estimates. In addition, we present new results on the GW emission from postbounce convective overturn and protoneutron star g-mode pulsations based on axisymmetric radiation-hydrodynamic calculations. Galactic core-collapse supernovae are very rare events, but within 3-5 Mpc from Earth, the rate jumps to 1 in ~2 years. Using the set of currently available theoretical gravitational waveforms, we compute upper-limit optimal signal-to-noise ratios based on current and advanced LIGO/GEO600/VIRGO noise curves for the recent SN 2008bk which exploded at ~3.9 Mpc. While initial LIGOs cannot detect GWs emitted by core-collapse events at such a distance, we find that advanced LIGO-class detectors could put significant upper limits on the GW emission strength for such events. We study the potential occurrence of the various GW emission processes in particular supernova explosion scenarios and argue that the GW signatures of neutrino-driven, magneto-rotational, and acoustically-driven core-collapse SNe may be mutually exclusive. We suggest that even initial LIGOs could distinguish these explosion mechanisms based on the detection (or non-detection) of GWs from a galactic core-collapse supernova.