Detectability of the gravitational-wave background produced by magnetar giant flares

TL;DR

This paper evaluates the potential detectability of a gravitational-wave background from magnetar giant flares, concluding that current third-generation detectors are unlikely to observe such signals given realistic astrophysical parameters.

Contribution

It provides analytic estimates of gravitational-wave signals from magnetar flares and assesses their detectability with future gravitational-wave observatories.

Findings

Gravitational-wave background from magnetar flares is likely undetectable with third-generation detectors.

Derived minimum magnetic field strength and flare rate for potential detection.

Discussed implications of current magnetar flare models on gravitational-wave observability.

Abstract

We study the gravitational-wave background produced by f-mode oscillations of neutron stars triggered by magnetar giant flares. For the gravitational-wave energy, we use analytic formulae obtained via general relativistic magnetohydrodynamic simulations of strongly magnetized neutron stars. Assuming the magnetar giant flare rate is proportional to the star-formation rate, we show the gravitational-wave signal is likely undetectable by third-generation detectors such as the Einstein Telescope and Cosmic Explorer. We calculate the minimum value of the magnetic field and the magnetar giant flare rate necessary for such a signal to be detectable, and discuss these in the context of our current understanding of magnetar flares throughout the Universe.