Jetted and Turbulent Stellar Deaths: New LVK-Detectable Gravitational Wave Sources

TL;DR

This paper predicts a new class of gravitational wave sources from massive star deaths involving jets and cocoons, which could be detected by current and future GW observatories, offering insights into stellar collapse and jet dynamics.

Contribution

The study introduces a novel GW source model from jet-driven stellar explosions, supported by 3D simulations, highlighting potential detectability and multi-messenger signals.

Findings

Cocoons emit quasi-isotropic GWs in the 10-100 Hz band.

Detection rate could reach ~10 events/year with third-generation detectors.

Wobbling jets significantly increase GW detectability.

Abstract

Upcoming LIGO/Virgo/KAGRA (LVK) observing runs are expected to detect a variety of inspiralling gravitational-wave (GW) events, that come from black-hole and neutron-star binary mergers. Detection of non-inspiral GW sources is also anticipated. We report the discovery of a new class of non-inspiral GW sources - the end states of massive stars - that can produce the brightest simulated stochastic GW burst signal in LVK bands known to date, and could be detectable in the LVK run A+. Some dying massive stars launch bipolar relativistic jets, which inflate a turbulent energetic bubble - cocoon - inside of the star. We simulate such a system using state-of-the-art 3D general-relativistic magnetohydrodynamic simulations and show that these cocoons emit quasi-isotropic GW emission in the LVK band, $\sim 10-100$ Hz, over a characteristic jet activity timescale, $\sim 10-100$ s. Our first-principles simulations show that jets exhibit a wobbling behavior, in which case cocoon-powered GWs might be detected already in LVK run A+, but it is more likely that these GWs will be detected by the third generation GW detectors with estimated rate of $ \sim 10 $ events/year. The detection rate drops to $ \sim 1\% $ of that value if all jets were to feature a traditional axisymmetric structure instead of a wobble. Accompanied by electromagnetic emission from the energetic core-collapse supernova and the cocoon, we predict that collapsars are powerful multi-messenger events.