Gravitational Waves as a Probe of Core Collapse Supernova Progenitor Structure

TL;DR

This study predicts gravitational wave signals from two supernova models with different internal structures, demonstrating potential for gravitational wave observations to reveal details of stellar interiors.

Contribution

It provides the first comparison of gravitational wave signals from supernova progenitors with nearly identical masses but different internal structures, linking GW features to explosion dynamics.

Findings

More compact progenitors produce larger GW strains and energy.

Faster contraction correlates with steeper gfF evolution.

GW signals reflect progenitor internal structure differences.

Abstract

We present the gravitational wave predictions from two-dimensional core collapse supernova (CCSN) simulations initiated from two nearly identical progenitors that have significantly different internal structures due to their late-stage stellar evolution. At the time of collapse, the 15.78 $M_{\odot}$ and 15.79 $M_{\odot}$ progenitors have compactness parameters $\xi_{2.5}$ of 0.136 and 0.206, respectively. We connect several features of the gravitational wave signal from each model to its previously explored explosion dynamics. In particular, the greater accretion onto the PNS of the more compact model is evident in broad-band frequency features with larger amplitude gravitational wave strains and greater gravitational wave energy release when compared to the less compact model. Additionally, the faster contraction rate of the more compact model is reflected in the $\sim$26% greater slope of the $g$-/$f$-mode feature (gfF) evolution of the gravitational wave signal. This work shows that in principle gravitational wave detection may provide information about interior stellar structure.