Estimate of the Detectability of the Circular Polarisation Signature of Supernova Gravitational Waves Using the Stokes Parameters

TL;DR

This study assesses the potential to detect circular polarisation in gravitational waves from supernovae using a new algorithm, finding high detectability within 5 kpc but not beyond 10 kpc, with implications for understanding supernova core features.

Contribution

Developed the Stokes Circular Polarisation algorithm integrated with coherent WaveBurst for estimating gravitational wave polarisation detectability.

Findings

High detectability of V mode at 2 and 5 kpc distances.

No significant V mode detection at 10 kpc.

Detectability correlates with the recoverability of GW polarizations.

Abstract

The circular polarisation of gravitational waves from core collapse supernovae has been proposed as a probe to investigate the rotation and physical features inside the core of the supernovae. However, it is still unclear as to how detectable the circular polarisation of gravitational waves will be. We developed an algorithm referred to as the Stokes Circular Polarisation algorithm for the computation of the Stokes parameters that works with the burst search pipeline coherent WaveBurst. Employing the waveform SFHx and the algorithm, we estimate the detectability of the circular polarisation signatures (V mode of the Stokes parameters) for sources across the sky at three different distances 2, 5, and 10 kpc, for a network of gravitational wave detectors consisted of advanced LIGO, advanced VIRGO and KAGRA. Using the Bayes factor, we found that for 2 kpc and 5 kpc, the majority of the sources (99.9% and 58.2% respectively) will have their V mode detectable, while for 10 kpc, no significant V mode is detectable. In addition, the significance of the V mode signature are consistent with the recoverability of the two polarisations of gravitational waves with respect to the network.