Magnetic-distortion-induced ellipticity and gravitational wave radiation of neutron stars: millisecond magnetars in short GRBs, Galactic pulsars, and magnetars

Abstract

Neutron stars may sustain a non-axisymmetric deformation due to magnetic distortion and are potential sources of continuous gravitational waves (GWs) for ground-based interferometric detectors. With decades of searches using available GW detectors, no evidence of a GW signal from any pulsar has been observed. Progressively stringent upper limits of ellipticity have been placed on Galactic pulsars. In this work, we use the ellipticity inferred from the putative millisecond magnetars in short gamma-ray bursts (SGRBs) to estimate their detectability by current and future GW detectors. For $\sim 1$ ms magnetars inferred from the SGRB data, the detection horizon is $\sim 30$ Mpc and $\sim 600$ Mpc for advanced LIGO (aLIGO) and Einstein Telescope (ET), respectively. Using the ellipticity of SGRB millisecond magnetars as calibration, we estimate the ellipticity and gravitational wave strain of Galactic pulsars and magnetars assuming that the ellipticity is magnetic-distortion-induced. We find that the results are consistent with the null detection results of Galactic pulsars and magnetars with the aLIGO O1. We further predict that the GW signals from these pulsars/magnetars may not be detectable by the currently designed aLIGO detector. The ET detector may be able to detect some relatively low frequency signals ($<50$ Hz) from some of these pulsars. Limited by its design sensitivity, the eLISA detector seems not suitable for detecting the signals from Galactic pulsars and magnetars.

Accepted for publication in ApJ

References in corpus (10)

• Advanced LIGO
• LIGO: The Laser Interferometer Gravitational-Wave Observatory
• X-Ray Flares from Postmerger Millisecond Pulsars
• The rate, luminosity function and time delay of non-Collapsar short GRBs
• The Millisecond Magnetar Central Engine in short GRBs
• Modelling magnetically deformed neutron stars
• GRB afterglow plateaus and Gravitational Waves: multi-messenger signature of a millisecond magnetar?
• Mountains on Neutron Stars: Accreted vs. Non-Accreted crusts
• A directed search for gravitational waves from Scorpius X-1 with initial LIGO
• Gravitational Waves from Pulsars and Their Braking Indices: The Role of a Time Dependent Magnetic Ellipticity

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• Constraining the ellipticity of new-born magnetar with the observational data of Long gamma-ray bursts
• Evolution of magnetic deformation in neutron star crust
• Constraining the nuclear equation of state via gravitational-wave radiation of short gamma-ray burst remnants
• The impact of superconductivity and the Hall effect in models of magnetized neutron stars
• Ultra-compact binary pulsars as continuous dual-line gravitational wave sources
• The evolution effects of radius and moment of inertia for rapidly rotating neutron stars
• Investigating magnetically-induced distortions of neutron stars through gamma-ray burst X-ray plateaus
• Prospects for the Observation of Continuous Gravitational Waves from Deformed Fast-spinning White Dwarfs