论文标题
三重系统中的自旋和偏心演变:从利多夫 - 科泽相互作用到内部二进制的最终合并
Spin and Eccentricity Evolution in Triple Systems: from the Lidov-Kozai Interaction to the Final Merger of the Inner Binary
论文作者
论文摘要
我们研究黑洞(BH)二进制的旋转和偏心率演变,这些二进制受到第三级肿块的影响,并体验了Lidov-Kozai(LK)激发。我们专注于三个方面。首先,我们研究了Antonini等人概述的方法,研究内部二进制的自旋轨道对齐。 [MNRAS 480,L58(2018)]以及Liu和Lai [APJ 863,68(2018)],但允许旋转具有随机的初始方向。我们证实了一个动力吸引子的存在,该动力吸引子将LK演变末端的自旋角度驱动到由旋转和外轨道角动量之间的初始角度给出的值(而不是有效自旋的特定值)。其次,我们进一步遵循(内部)二进制的演变,以研究最终的自旋旋转对准。我们将有效的潜在理论推广到包括轨道偏心率,这使我们能够在灵感早期阶段有效地发展系统。我们进一步发现,自旋旋转和自旋轨道对齐是相关的,并且相关性由初始自旋角度确定。对于最初在轨道平面中的自旋矢量的系统,最终旋转强烈不利于对齐的构型,因此可能导致GW后坐力的值比均匀的自旋旋转比对预测的要大。最后,我们研究在LK过程中可以实现的最大偏心率激发,包括重力波辐射的影响。我们发现,当三级质量是超质量的BH,并且内部二进制质量很大,即使有最大的LK激发,当二进制轨道频率达到10 Hz时,剩余偏心率通常小于0.1,并且必须遵循这种系统系统的轨道进化。
We study the spin and eccentricity evolution of black-hole (BH) binaries that are perturbed by tertiary masses and experience the Lidov-Kozai (LK) excitation. We focus on three aspects. Firstly, we study the spin-orbit alignment of the inner binary following the approach outlined by Antonini et al. [MNRAS 480, L58 (2018)] and Liu and Lai [ApJ 863, 68 (2018)], yet allowing the spins to have random initial orientations. We confirm the existence of a dynamical attractor that drives the spin-orbit angle at the end of the LK evolution to a value given by the initial angle between the spin and the outer orbital angular momentum (instead of to a specific value of the effective spin). Secondly, we follow the (inner) binary's evolution further to the merger to study the final spin-spin alignment. We generalize the effective potential theory to include orbital eccentricity, which allows us to efficiently evolve the system in the early inspiral stages. We further find that the spin-spin and spin-orbit alignments are correlated and the correlation is determined by the initial spin-orbit angle. For systems with the spin vectors initially in the orbital plane, the final spins strongly disfavor an aligned configuration and could thus lead to a greater value of the GW recoil than a uniform spin-spin alignment would predict. Lastly, we study the maximum eccentricity excitation that can be achieved during the LK process, including the effects of gravitational-wave radiation. We find that when the tertiary mass is a super-massive BH and the inner binary is massive, then even with the maximum LK excitation, the residual eccentricity is typically less than 0.1 when the binary's orbital frequency reaches 10 Hz, and a decihertz detector would be necessary to follow such a system's orbital evolution.