Magnetic-distortion-induced Ellipticity and Gravitational Wave Radiation of Neutron Stars: Millisecond Magnetars in Short GRBs, Galactic Pulsars, and Magnetars

Journal Article · Tue Aug 01 04:00:00 EDT 2017 · Astrophysical Journal

DOI:https://doi.org/10.3847/1538-4357/AA7D00· OSTI ID:22663334

Gao, He; Cao, Zhoujian ^[1]; Zhang, Bing ^[2]

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1. Department of Astronomy, Beijing Normal University, Beijing 100875 (China)
2. Department of Physics and Astronomy, University of Nevada Las Vegas, NV 89154 (United States)

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 ∼1 ms magnetars inferred from the SGRB data, the detection horizon is ∼30 Mpc and ∼600 Mpc for the advanced LIGO (aLIGO) and Einstein Telescope (ET), respectively. Using the ellipticity of SGRB millisecond magnetars as calibration, we estimate the ellipticity and GW 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 to not be suitable for detecting the signals from Galactic pulsars and magnetars.

• OSTI ID: 22663334
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 2 Vol. 844; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
AXIAL SYMMETRY
CALIBRATION
COSMIC GAMMA BURSTS
DEFORMATION
DETECTION
GAMMA RADIATION
GRAVITATIONAL WAVES
INTERFEROMETRY
NEUTRON STARS
PULSARS
SENSITIVITY
STRAINS
TELESCOPES