论文标题
涉及行星系统在出生环境中的遭遇：二进制的重要作用
Encounters involving planetary systems in birth environments: the significant role of binaries
论文作者
论文摘要
大多数恒星在聚类环境中形成。单恒星和二进制恒星有时都会在这种拥挤的环境中遇到行星系统。二进制文件的相遇率可能大于单星，即使对于低至10-20％的二元分数也可能要大。在这项工作中，我们像年轻的簇一样，研究了一个太阳和二元和二元恒星和二元恒星之间的散射。我们首先进行了一组涉及二进制范围和单星范围的相遇的模拟，发现更宽的二进制室对行星的射出具有较大的横截面。其次，我们考虑在现实的人群中进行这种散射，为二进制物绘制参数，并从观察到的人群中绘制单星。散射结果是多种多样的，包括弹射，捕获/交换和碰撞。二进制文件比单颗恒星更有效，在导致地球的射出和碰撞时，二进制文件比单颗恒星更有效。因此，在群集中，只要二进制部分大于大约10％，二进制文件就会以这两个结果来占主导地位。 For an open cluster of a stellar density 50 pc$^{-3}$, a lifetime 100 Myr and a binary fraction 0.5, we estimate that of the order of 1 per cent of the Jupiters are ejected, 0.1 per cent collide with a star, 0.1 per cent change ownership and 10 per cent of the Sun-Jupiter pairs acquire a stellar companion during scatterings.这些同伴通常是1000次的Au远处，而在一半的情况下（占所有太阳jupiter对的5％），他们可以通过Kozai-Lidov机制激发行星的轨道，然后再被后来的相遇。我们的结果表明，太阳系可能曾经在其出生集群中有一个伴侣。
Most stars form in a clustered environment. Both single and binary stars will sometimes encounter planetary systems in such crowded environments. Encounter rates for binaries may be larger than for single stars, even for binary fractions as low as 10-20 per cent. In this work, we investigate scatterings between a Sun-Jupiter pair and both binary and single stars as in young clusters. We first perform a set of simulations of encounters involving wide ranges of binaries and single stars, finding that wider binaries have larger cross sections for the planet's ejection. Secondly, we consider such scatterings in a realistic population, drawing parameters for the binaries and single stars from the observed population. The scattering outcomes are diverse, including ejection, capture/exchange and collision. The binaries are more effective than single stars by a factor of several or more in causing the planet's ejection and collision. Hence, in a cluster, as long as the binary fraction is larger than about 10 per cent, the binaries will dominate the scatterings in terms of these two outcomes. For an open cluster of a stellar density 50 pc$^{-3}$, a lifetime 100 Myr and a binary fraction 0.5, we estimate that of the order of 1 per cent of the Jupiters are ejected, 0.1 per cent collide with a star, 0.1 per cent change ownership and 10 per cent of the Sun-Jupiter pairs acquire a stellar companion during scatterings. These companions are typically 1000s of au distant and in half of the cases (so 5 per cent of all Sun-Jupiter pairs), they can excite the planet's orbit through Kozai--Lidov mechanism before stripped by later encounters. Our result suggests that the Solar System may have once had a companion in its birth cluster.
