arXivDaily arXiv每日学术速递 周一至周五更新
arXiv周末暂无论文更新,休息一下吧,周末愉快~~
arXiv 1807.05901astro-ph.EP
收藏

由Lidov-Kozai旋回和潮汐摩擦研究三星系统的动力学演化

Dynamical evolution of triple-star systems by Lidov-Kozai cycles and tidal friction

Manon Bataille, Anne-Sophie Libert, Alexandre C. M. Correia

摘要:

许多三星系统都有一个轨道周期只有几天的内双星。解释观测中出现的短周期堆积的一个常见机制是通过Lidov-Kozai旋回与潮汐摩擦相结合的迁移。在这里,我们重新审视这一机制,并旨在确定导致这一过程的初始轨道配置。我们表明,三星系统的相互倾斜度并不是唯一的关键参数,因为偏心率以及内轨道近心点的辐角在Lidov-Kozai迁移的建立中也发挥了重要作用。我们的框架是长期分层三体问题(八极近似)与广义相对论修正,包括潮汐,恒星扁率和磁自旋制动的影响。轨道和自旋的演变被认为是。进行了大量的数值模拟与均匀和非均匀分布的初始轨道参数,和无偏的初始条件导致Lidov-Kozai迁移被揭示。最后,我们强调了初始“Kozai常数”$h=\sqrt{(1-e^2)}\cos{i}$在三星系统的动力学演化中的重要性,通过显示在给定的$h$值下的相图揭示了不同的演化路径。

英文摘要:

Many triple-star systems have an inner pair with an orbital period of a few days only. A common mechanism to explain the short-period pile-up present in the observations is the migration through Lidov-Kozai cycles combined with tidal friction. Here, we revisit this mechanism and aim to determine the initial orbital configurations leading to this process. We show that the mutual inclination of the triple-star system is not the only critical parameter, since the eccentricity as well as the argument of the pericenter of the inner orbit also play an important role in the establishment of the Lidov-Kozai migration. Our framework is the secular hierarchical three-body problem (octupole order approximation) with general relativity corrections, including the effects of tides, stellar oblateness and magnetic spin-down braking. Both the orbital and the spin evolutions are considered. Extensive numerical simulations with uniform and non-uniform distributions of the initial orbital parameters are carried out, and unbiased initial conditions leading to Lidov-Kozai migration are revealed. Finally, we highlight the importance of the initial "Kozai constant" $h=\sqrt{(1-e^2)}\cos{i}$ in the dynamical evolution of triple-star systems, by showing that phase portraits at given $h$-values unveil different evolution paths.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑