Survivability of planetary systems in young and dense star clusters
Survivability of planetary systems in young and dense star clusters
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DOI：
10.1051/0004-6361/201834641
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发表时间：
2019-02
影响因子：
6.5
通讯作者：
A. V. Elteren;S. Zwart;I. Pelupessy;Maxwell X. Cai;S. McMillan
中科院分区：
文献类型：
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作者：
A. V. Elteren;S. Zwart;I. Pelupessy;Maxwell X. Cai;S. McMillan
目标。我们进行了模拟使用的猎户座梯形星星集群的恒星的演化和行星系统的动力学的天体物理多用途软件环境。方法.从早期的模拟的初始条件中选择的大小和质量分布的观察到的拱星盘在这个集群是令人满意的再现。每颗星星有四、五颗或大小的行星被引入到500颗类太阳恒星的轨道上，最大轨道间距为400 Au。结果我们的研究重点是自由浮动行星的生产。在模拟的初始条件下，总共有357颗行星从总共2522颗行星中脱离出来。其中，281颗在穿越星星的时间尺度内离开星团;其他的则作为自由漂浮的星团内行星留在星团内。其中五颗自由漂浮的星团内行星在稍后的时间被另一颗星星捕获。结论.行星从其宿主星星中消失的两个主要机制是，与另一颗星星强烈相遇时的抛射或内部行星散射，驱动蒸发与行星出生时的轨道分离质量无关。由于星系团势的缓慢变化而引起的小扰动对行星系统的演化具有重要意义。此外，星星失去行星的概率与行星质量无关，也与其初始轨道分离无关。因此，自由漂浮的行星的质量分布与被其宿主星星束缚的行星的质量分布是无法区分的。
Aims. We perform a simulation using the Astrophysical Multipurpose Software Environment of the Orion Trapezium star cluster in which the evolution of the stars and the dynamics of planetary systems are taken into account. Methods. The initial conditions from earlier simulations were selected in which the size and mass distributions of the observed circumstellar disks in this cluster are satisfactorily reproduced. Four, five, or size planets per star were introduced in orbit around the 500 solar-like stars with a maximum orbital separation of 400 au. Results. Our study focuses on the production of free-floating planets. A total of 357 become unbound from a total of 2522 planets in the initial conditions of the simulation. Of these, 281 leave the cluster within the crossing timescale of the star cluster; the others remain bound to the cluster as free-floating intra-cluster planets. Five of these free-floating intra-cluster planets are captured at a later time by another star. Conclusions. The two main mechanisms by which planets are lost from their host star, ejection upon a strong encounter with another star or internal planetary scattering, drive the evaporation independent of planet mass of orbital separation at birth. The effect of small perturbations due to slow changes in the cluster potential are important for the evolution of planetary systems. In addition, the probability of a star to lose a planet is independent of the planet mass and independent of its initial orbital separation. As a consequence, the mass distribution of free-floating planets is indistinguishable from the mass distribution of planets bound to their host star.