非均匀 rubble pile 的灾难性潮汐瓦解：两种机制的故事
Catastrophic tidal disruption of heterogeneous rubble piles: a tale of two regimes
AI总结：
本研究通过N-body代码GRAINS模拟6种非均匀 rubble pile 与地球的潮汐交会，识别出两种潮汐瓦解机制，发现 rubble pile 的颗粒形状和尺寸分布等非均匀性会显著影响潮汐瓦解结果，未来研究需考虑这些参数。
AI中文摘要：
rubble pile 天体在潮汐力作用下发生形变或瓦解的方式与其内部强度和结构直接相关。对这类潮汐瓦解事件的数值模拟是约束太阳系小天体起源与演化不可或缺的数值实验室。以往多数关于 rubble pile 潮汐瓦解的研究主要考虑由等尺寸球形颗粒组成的母体。本研究通过改变颗粒形状和尺寸频率分布，填补了现有研究中关于集合体非均匀性对潮汐瓦解结果影响的空白；这类非均匀性已被证实对 rubble pile 的撞击和旋转失效动力学有显著影响。我们使用 N-body 代码 GRAINS，对6种不同的 rubble pile 母体与地球之间的抛物线和双曲线潮汐交会进行了数值模拟。不同母体产生的碎片质量分布和潮汐链形态，进一步与 rubble pile 的内部强度相关联。研究识别出两种潮汐瓦解机制：第一种是最靠近行星的机制，其动力学演化由潮汐力主导，在此机制中，颗粒形状、尺寸分布和分辨率对最终的碎片质量分布影响很小；第二种是剪切控制机制，母体的内部结构开始强烈影响最终的潮汐链形态和幸存碎片的性质。 rubble pile 模型中颗粒形状和尺寸频率分布产生的非均匀性，对潮汐瓦解事件的结果有显著影响。未来研究尝试将数值模型结果与观测结果关联时，必须仔细考虑这些参数。
英文摘要：
The way a rubble-pile body deforms or disrupts under the influence of tidal forces can be directly tied to its internal strength and configuration. Computational modelling of such tidal disruption events provides an indispensable numerical laboratory for constraining the origin and evolution of small bodies in the Solar System. A majority of previous investigations into tidal disruption of rubble piles have mainly considered progenitors consisting of same-sized, spherical elements. Our study attempts to fill the existing gap in studies analysing the effect of aggregate heterogeneity on tidal disruption outcomes by varying element shape and size frequency distribution. Such heterogeneities have been shown to strongly influence rubble pile dynamics for impacts and rotational failure. We performed numerical simulations of parabolic and hyperbolic tidal encounters between six unique rubble-pile progenitors and the Earth using the N-body code GRAINS. The resulting mass distributions of generated fragments and tidal chain morphologies for the different progenitors were further tied to the internal strength of rubble piles. Two regimes of tidal disruption are identified. In the first regime, closest to the planet, the dynamic evolution is dominated by tidal forces. Here, particle shape, size distribution and resolution appear to have little importance for the resulting distribution of fragment masses. In the second, shear-controlled regime, the internal structure of the progenitor begins to strongly influence the resulting tidal chain morphology and properties of the surviving fragments. Heterogeneity originating from the shape and size frequency distribution of elements in rubble pile models has a substantial effect on the outcomes of tidal disruption events. These parameters must be carefully taken into account when future studies attempt to tie results from numerical models to observations.
