论文标题
使用丘陵机制产生重复的部分潮汐破坏事件和asassn-14KO
Using the Hills Mechanism to Generate Repeating Partial Tidal Disruption Events and ASASSN-14ko
论文作者
论文摘要
已经发现了频率越来越高的周期性核瞬变，其中一个系统（Asassn-14KO）在$ 114 \ pm的时间表上表现出高度定期的爆发1美元。据推测，该来源的爆发是由恒星反复局部破坏产生的，但是如何将恒星放置在超级质量黑洞的如此紧密的轨道上仍不清楚。在这里，我们使用分析性论证和三体积分来证明，山洞系统被黑洞的潮汐破坏，可以导致在$ \ sim 114 $ Day Orbit上捕获一颗恒星，并且具有与二元二元中一颗星星的潮汐半径相当。因此，山丘捕获可以在紧密结合的轨道上产生恒星，从而反复局部破坏，从而导致可行的机制，不仅会产生从asassn-14KO中检测到的爆发，而且通常是针对周期性的核瞬变。我们还表明，由于重力波发射而导致的捕获恒星周期的变化速率可能太小，无法为Asassn-14KO产生观察到的值，这表明在该系统中，必须有其他影响轨道衰减的其他效果。但是，通常，重力波排放对于限制这些系统的寿命可能很重要，并且可能在未来事件中产生可观察到的时期衰减率。
Periodic nuclear transients have been detected with increasing frequency, with one such system -- ASASSN-14ko -- exhibiting highly regular outbursts on a timescale of $114 \pm 1$ days. It has been postulated that the outbursts from this source are generated by the repeated partial disruption of a star, but how the star was placed onto such a tightly bound orbit about the supermassive black hole remains unclear. Here we use analytic arguments and three-body integrations to demonstrate that the Hills mechanism, where a binary system is destroyed by the tides of the black hole, can lead to the capture of a star on a $\sim 114$ day orbit and with a pericenter distance that is comparable to the tidal radius of one of the stars within the binary. Thus, Hills capture can produce stars on tightly bound orbits that undergo repeated partial disruption, leading to a viable mechanism for generating not only the outbursts detected from ASASSN-14ko, but for periodic nuclear transients in general. We also show that the rate of change of the period of the captured star due to gravitational-wave emission is likely too small to produce the observed value for ASASSN-14ko, indicating that in this system there must be additional effects that contribute to the decay of the orbit. In general, however, gravitational-wave emission can be important for limiting the lifetimes of these systems, and could produce observable period decay rates in future events.
