Details
| Original language | English |
|---|---|
| Article number | abd256 |
| Journal | Astrophysical Journal Letters |
| Volume | 906 |
| Issue number | 2 |
| Publication status | Published - 13 Jan 2021 |
Abstract
We present the results of a search in LIGO O2 public data for continuous gravitational waves from the neutron star in the low-mass X-ray binary Scorpius X-1. We search for signals with ≈ constant frequency in the range 40-180Hz. Thanks to the efficiency of our search pipeline we can use a long coherence time and achieve unprecedented sensitivity, significantly improving on existing results. This is the first search that has been able to probe gravitational wave amplitudes that could balance the accretion torque at the neutron star radius. Our search excludes emission at this level between 67.5 and 131.5 Hz, for an inclination angle 44° ± 6° derived from radio observations, and assuming that the spin axis is perpendicular to the orbital plane. If the torque arm is ≈26 km-a conservative estimate of the Alfvén radius -our results are more constraining than the indirect limit across the band. This allows us to exclude certain mass-radius combinations and to place upper limits on the strength of the star's magnetic field with a different probe than ever used before. We also correct a mistake that appears in the literature in the equation that gives the gravitational wave amplitude at the torque balance and we re-interpret the associated latest LIGO/Virgo results in light of this.
ASJC Scopus subject areas
- Physics and Astronomy(all)
- Astronomy and Astrophysics
- Earth and Planetary Sciences(all)
- Space and Planetary Science
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In: Astrophysical Journal Letters, Vol. 906, No. 2, abd256, 13.01.2021.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Search for Continuous Gravitational Waves from Scorpius X-1 in LIGO O2 Data
AU - Zhan, Yuanhao
AU - Papa, Maria Alessandra
AU - Krishnan, Badri
AU - Watts, Anna L.
N1 - Funding Information: The computation of the work was run on the ATLAS computing cluster at AEI Hannover AEI (2017) funded by the Max Planck Society and the State of Niedersachsen, Germany. A.L.W. acknowledges support from ERC Consolidator grant No.865768 AEONS (PI: Watts). We thank Colin Capano for providing the data from his paper in a convenient format and for the helpful discussions. We thank John T. Whelan for his careful reading of our paper and the useful comments. This research has made use of data, software, and/or web tools obtained from the LIGO Open Science Center (https://losc. ligo.org), a service of LIGO Laboratory, the LIGO Scientific Collaboration and the Virgo Collaboration. LIGO is funded by the U.S. National Science Foundation. Virgo is funded by the French Centre National de Recherche Scientifique (CNRS), the Italian Istituto Nazionale della Fisica Nucleare (INFN) and the Dutch Nikhef, with contributions by Polish and Hungarian institutes.
PY - 2021/1/13
Y1 - 2021/1/13
N2 - We present the results of a search in LIGO O2 public data for continuous gravitational waves from the neutron star in the low-mass X-ray binary Scorpius X-1. We search for signals with ≈ constant frequency in the range 40-180Hz. Thanks to the efficiency of our search pipeline we can use a long coherence time and achieve unprecedented sensitivity, significantly improving on existing results. This is the first search that has been able to probe gravitational wave amplitudes that could balance the accretion torque at the neutron star radius. Our search excludes emission at this level between 67.5 and 131.5 Hz, for an inclination angle 44° ± 6° derived from radio observations, and assuming that the spin axis is perpendicular to the orbital plane. If the torque arm is ≈26 km-a conservative estimate of the Alfvén radius -our results are more constraining than the indirect limit across the band. This allows us to exclude certain mass-radius combinations and to place upper limits on the strength of the star's magnetic field with a different probe than ever used before. We also correct a mistake that appears in the literature in the equation that gives the gravitational wave amplitude at the torque balance and we re-interpret the associated latest LIGO/Virgo results in light of this.
AB - We present the results of a search in LIGO O2 public data for continuous gravitational waves from the neutron star in the low-mass X-ray binary Scorpius X-1. We search for signals with ≈ constant frequency in the range 40-180Hz. Thanks to the efficiency of our search pipeline we can use a long coherence time and achieve unprecedented sensitivity, significantly improving on existing results. This is the first search that has been able to probe gravitational wave amplitudes that could balance the accretion torque at the neutron star radius. Our search excludes emission at this level between 67.5 and 131.5 Hz, for an inclination angle 44° ± 6° derived from radio observations, and assuming that the spin axis is perpendicular to the orbital plane. If the torque arm is ≈26 km-a conservative estimate of the Alfvén radius -our results are more constraining than the indirect limit across the band. This allows us to exclude certain mass-radius combinations and to place upper limits on the strength of the star's magnetic field with a different probe than ever used before. We also correct a mistake that appears in the literature in the equation that gives the gravitational wave amplitude at the torque balance and we re-interpret the associated latest LIGO/Virgo results in light of this.
UR - http://www.scopus.com/inward/record.url?scp=85100144901&partnerID=8YFLogxK
U2 - 10.3847/2041-8213/abd256
DO - 10.3847/2041-8213/abd256
M3 - Article
AN - SCOPUS:85100144901
VL - 906
JO - Astrophysical Journal Letters
JF - Astrophysical Journal Letters
SN - 2041-8205
IS - 2
M1 - abd256
ER -