Circular polarizations of gravitational waves from core-collapse supernovae: a clear indication of rapid rotation

TL;DR

This paper suggests that detecting circular polarization in gravitational waves from core-collapse supernovae can serve as a clear indicator of rapid core rotation, with potential detection up to the far side of the Galaxy.

Contribution

It introduces the idea that circular polarization of gravitational waves can indicate rapid rotation in supernova cores, supported by simulation-based analysis.

Findings

Circular polarization signals are linked to non-axisymmetric fluid motions.

Detection is feasible with second-generation gravitational wave detectors.

Rapid rotation (period < a few seconds) enhances detectability)

Abstract

We propose to employ the circular polarization of gravitational waves emitted by core-collapse supernovae as an unequivocal indication of rapid rotation deep in their cores. It has been demonstrated by three dimensional simulations that non-axisymmetric accretion flows may develop spontaneously via hydrodynamical instabilities in the post-bounce cores. It is not surprising then that the gravitational waves emitted by such fluid motions are circularly polarized. We show in this letter that a network of the second generation detectors of gravitational waves worldwide may be able to detect such polarizations up to the opposite side of Galaxy as long as the rotation period is shorter than a few seconds prior to collapse.