Search for Long-duration Gravitational-wave Signals Associated with Magnetar Giant Flares

TL;DR

This paper investigates the potential for detecting gravitational waves from magnetar giant flares using advanced detectors, highlighting the importance of sensitivity improvements for future observations.

Contribution

It introduces a new gravitational-wave search algorithm and assesses detection prospects for magnetar flares with current and future detectors.

Findings

No gravitational waves detected from four analyzed flares.

Detection of at least 1% energy emission possible with advanced detectors.

Future third-generation detectors could significantly improve detection prospects.

Abstract

Magnetar giant flares are rare and highly energetic phenomena observed in the transient sky whose emission mechanisms are still not fully understood. Depending on the nature of the excited modes of the magnetar, they are also expected to emit gravitational waves, which may bring unique information about the dynamics of the excitation. A few magnetar giant flares have been proposed to be associated to short gamma-ray bursts. In this paper we revisit, with a new gravitational-wave search algorithm, the possible emission of gravitational waves from four magnetar giant flares within 5 Mpc. While no gravitational-wave signals were observed, we discuss the future prospects of detecting signals with more sensitive gravitational-wave detectors. We in particular show that galactic magnetar giant flares that emit at least 1% of their electromagnetic energy as gravitational waves could be detected during the planned observing run of the LIGO and Virgo detectors at design sensitivity, with even better prospects for third generation detectors.