论文标题
第三星的径向速度变化，绕着共面和非环形三元组绕二进制黑洞旋转：短期和长期异常行为
Radial-velocity variation of a tertiary star orbiting a binary black hole in coplanar and non-coplanar triples: short- and long-term anomalous behavior
论文作者
论文摘要
在不久的将来，许多正在进行的调查可能会在我们的银河系中发现星光洞二进制。其中的一小部分可能是包含内部二进制的三重系统，而不是一个黑洞，这可能是现在从重力波中常规发现的二进制黑洞（BBH）的祖细胞。我们扩展了以前的提议，以从Coplanar Triples中三级恒星的短期径向速度（RV）变化中定位内部BBH，我们也考虑了非Coplanar Triples及其长期RV变化。具体而言，我们假设共面和非卡拉纳尔三元组，其内部BBH为$ 20〜m_ \ odot $，其外轨道和内轨道周期分别为80天和10天。我们执行一系列N体模拟，并将结果与基于四极扰动理论的分析近似解决方案进行比较。对于共面三元组，外部星的周围移位可用于检测隐藏的内部BBH。对于非平球三元组，外部恒星的总RV半振幅会定期根据$ 100 $ km/s的订单调节，这是由于其对Kozai-Lidov振荡时间尺度的进步。这种长期调制将在十年内检测到，与$ 100 $ m/s的短期RV变化无关，大约是内部二进制的轨道频率的两倍。因此，对未来的星际黑洞二进制候选者的RV监视提供了一种有希望的方法，可在光条中搜索其内部隐藏BBH。
A number of ongoing surveys are likely to discover star-black hole binaries in our Galaxy in the near future. A fraction of them may be triple systems comprising an inner binary, instead of a single black hole, which might be progenitors of binary black holes (BBHs) routinely discovered now from the gravitational wave. We extend our previous proposal to locate inner BBHs from the short-term radial-velocity (RV) variation of a tertiary star in coplanar triples, and we consider noncoplanar triples and their long-term RV variations as well. Specifically, we assume coplanar and noncoplanar triples with an inner BBH of the total mass $20~M_\odot$, whose outer and inner orbital periods are 80 days and 10 days, respectively. We perform a series of N-body simulations and compare the results with analytic approximate solutions based on quadrupole perturbation theory. For coplanar triples, the pericenter shift of the outer star can be used to detect the hidden inner BBH. For noncoplanar triples, the total RV semi-amplitude of the outer star is modulated periodically on the order of $100$km/s due to its precession over roughly the Kozai-Lidov oscillation timescale. Such long-term modulations would be detectable within a decade, independent of the short-term RV variations on the order of of $100$ m/s at roughly twice the orbital frequency of the inner binary. Thus the RV monitoring of future star-black hole binary candidates offers a promising method for searching for their inner hidden BBHs in optical bands.
