Effects of spin-orbit coupling on gravitational waveforms from a triaxial nonaligned neutron star in a binary system
Effects of spin-orbit coupling on gravitational waveforms from a triaxial nonaligned neutron star in a binary system
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DOI：
10.1103/physrevd.108.063035
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发表时间：
2023-07
影响因子：
5
通讯作者：
Wen-Fan Feng;Tan Liu;Jie-Wen Chen;Yan Wang;S. Mohanty
中科院分区：
文献类型：
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作者：
Wen-Fan Feng;Tan Liu;Jie-Wen Chen;Yan Wang;S. Mohanty
旋转的中子星（NS）可以发出连续的引力波（GW），这些引力波携带着关于致密物体的丰富信息。如果探测到这样的信号，它将为我们提供对极端条件下物质物理性质的新见解。未来的天基GW探测器，如丽莎和天琴，有可能探测到轨道周期小于10分钟的紧密双星中的双NS。在丽莎/天琴发现的这样一个双星系统中，成功地从旋转的NS中定向搜索连续GW的可能性将随着拟议的下一代地基GW天文台（如宇宙探测器和爱因斯坦望远镜）的建立而显著增加。从这样一个紧密的二元系统中搜索连续的GW需要高度精确的波形模板，这些模板可以解释NS与其同伴的相互作用。在这种精神下，我们推导出解析近似，描述了一个三轴非对齐NS在一个二进制系统中的自旋-轨道耦合的影响已被纳入发射的GWs。估计了孤立NS与广泛使用的波形的差异，并计算了使用Cosmic Explorer的示例信号的参数估计精度。对于一个典型的轨道周期为6 min的紧双NS系统，自旋进动对该双星中自旋NS的角频率修正为10 - 6 Hz，与轨道进动角频率处于同一数量级.几天后（$\sim 10^5~{\rm s}$），有自旋进动和无自旋进动的波形之间的拟合因子将下降到小于0.97。我们发现，自旋轨道耦合有可能提高参数估计的准确性，特别是对于二进制倾角和自旋进动锥开口角，由高达3个数量级。（节录）
Spinning neutron stars (NSs) can emit continuous gravitational waves (GWs) that carry a wealth of information about the compact object. If such a signal is detected, it will provide us with new insight into the physical properties of matter under extreme conditions. Future space-based GW detectors, such as LISA and TianQin, can potentially detect some double NSs in tight binaries with orbital periods shorter than 10 minutes. The possibility of a successful directed search for continuous GWs from the spinning NS in such a binary system identified by LISA/TianQin will be significantly increased with the proposed next-generation ground-based GW observatories, such as Cosmic Explorer and Einstein Telescope. Searching for continuous GWs from such a tight binary system requires highly accurate waveform templates that account for the interaction of the NS with its companion. In this spirit, we derive analytic approximations that describe the GWs emitted by a triaxial non-aligned NS in a binary system in which the effects of spin-orbit coupling have been incorporated. The difference with the widely used waveform for the isolated NS is estimated and the parameter estimation accuracy of an example signal using Cosmic Explorer is calculated. For a typical tight double NS system with a 6~min orbital period, the angular frequency correction of the spinning NS in this binary due to spin precession is $\sim 10^{-6}~{\rm Hz}$, which is in the same order of magnitude as the angular frequency of orbital precession. The fitting factor between the waveforms with and without spin precession will drop to less than 0.97 after a few days ($\sim 10^5~{\rm s}$). We find that spin-orbit coupling has the potential to improve the accuracy of parameter estimation, especially for the binary inclination angle and spin precession cone opening angle, by up to 3 orders of magnitude. (Abridged)