Modelling circumbinary protoplanetary disks II. Gas disk feedback on planetesimal dynamical and collisional evolution in the circumbinary systems Kepler-16 and 34
Modelling circumbinary protoplanetary disks II. Gas disk feedback on planetesimal dynamical and collisional evolution in the circumbinary systems Kepler-16 and 34
复制标题
模拟环双星原行星盘 II。
DOI：
10.1051/0004-6361/201628349
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发表时间：
2016
影响因子：
6.5
通讯作者：
Lines S
中科院分区：
文献类型：
--
作者：
Lines S
目标我们研究在进动偏心气盘的引力影响下，观测系统 Kepler-16 和 Kepler-34 周围的环双星原行星盘中星子生长的可行性。方法我们将之前对双星周围原行星盘的流体动力学模拟结果嵌入到 N 体代码中，以执行 3D、高分辨率、粒子间重力分析 星子生长和动力学的模拟，包括气体施加的引力。结果包括完整的进动不对称气盘，为在环双星空腔边缘运行的星子产生高偏心率轨道，其中气体表面密度和偏心率具有最大值。气盘能够有效地对齐某些区域的星子近心，从而形成定相的、非相互作用的轨道。在这些区域之外，偏心星子轨道变得错位和重叠，导致星子碰撞期间交叉轨道和高相对速度。这可能导致侵蚀性碰撞数量的增加，远远超过导致增长的碰撞数量。静态轴对称气盘的引力聚焦较弱，不会显着改变无气情况下的碰撞结果。结论由于气盘的不对称性，星子在高度偏心的轨道上受到强烈扰动。在星子轨道排列不佳的情况下，轨道交叉会导致侵蚀性碰撞次数的增加。这使得在 Kepler-16b 和 Kepler-34b 的位置很难发生持续的星子吸积，因此我们排除了原位生长的可能性。这进一步支持了我们最初的建议，即大多数绕双星运行的行星应该在圆盘更远的地方形成并向内迁移。
AimsWe investigate the feasibility of planetesimal growth in circumbinary protoplanetary disks around the observed systems Kepler-16 and Kepler-34 under the gravitational influence of a precessing eccentric gas disk.MethodsWe embed the results of our previous hydrodynamical simulations of protoplanetary disks around binaries into anN-body code to perform 3D, high-resolution, inter-particle gravity-enabled simulations of planetesimal growth and dynamics that include the gravitational force imparted by the gas.ResultsIncluding the full, precessing asymmetric gas disk generates high eccentricity orbits for planetesimals orbiting at the edge of the circumbinary cavity, where the gas surface density and eccentricity have their largest values. The gas disk is able to efficiently align planetesimal pericenters in some regions leading to phased, non-interacting orbits. Outside of these areas eccentric planetesimal orbits become misaligned and overlap leading to crossing orbits and high relative velocities during planetesimal collisions. This can lead to an increase in the number of erosive collisions that far outweighs the number of collisions that result in growth. Gravitational focusing from the static axisymmetric gas disk is weak and does not significantly alter collision outcomes from the gas free case.ConclusionsDue to asymmetries in the gas disk, planetesimals are strongly perturbed onto highly eccentric orbits. Where planetesimals orbits are not well aligned, orbit crossings lead to an increase in the number of erosive collisions. This makes it difficult for sustained planetesimal accretion to occur at the location of Kepler-16b and Kepler-34b and we therefore rule out in situ growth. This adds further support to our initial suggestions that most circumbinary planets should form further out in the disk and migrate inwards.