White dwarfs that exhibit transit signatures of planetary debris and accreted planetary material provide exceptional opportunities to probe the material composition and dynamical structure of planetary systems. Although previous theoretical work investigating the role of minor body disruption around white dwarfs has focused on spherical bodies, Solar system asteroids can be more accurately modelled as triaxial ellipsoids. Here, we present an analytical framework to identify the type of disruption (tidal fragmentation, total sublimation, or direct impact) experienced by triaxial asteroids approaching white dwarfs on extremely eccentric (e ∼ 1) orbits. This framework is then used to identify the outcomes for simplified Main belt analogues of 100 bodies across five different white dwarf temperatures. We also present an empirical relationship between cooling age and effective temperature for both DA and DB white dwarfs to identify the age of the white dwarfs considered here. We find that using a purely spherical shape model can underestimate the physical size and radial distance at which an asteroid is subjected to complete sublimation, and these differences increase with greater elongation of the body. Contrastingly, fragmentation always occurs in the largest semi-axis of a body and so can be modelled by a sphere of that radius. Both fragmentation and sublimation are greatly affected by the body’s material composition, and hence by the composition of their progenitor asteroid belts. The white dwarf temperature, and hence cooling age, can affect the expected debris distribution: higher temperatures sublimate large elongated asteroids, and cooler temperatures accommodate more direct impacts.

中文翻译：

---

白矮星行星碎片依赖于小行星带内的物理结构分布

白矮星表现出行星碎片和吸积行星物质的过境特征，为探索行星系统的物质成分和动态结构提供了绝佳的机会。尽管先前研究白矮星周围小天体破坏作用的理论工作主要集中在球体上，但太阳系小行星可以更准确地建模为三轴椭球体。在这里，我们提出了一个分析框架来确定三轴小行星在极偏心（e ~ 1）轨道上接近白矮星时所经历的破坏类型（潮汐破碎、完全升华或直接撞击）。然后，该框架用于确定 100 个天体在五个不同白矮星温度下的简化主带类似物的结果。我们还提出了 DA 和 DB 白矮星的冷却年龄和有效温度之间的经验关系，以确定这里考虑的白矮星的年龄。我们发现，使用纯球形模型会低估小行星完全升华的物理尺寸和径向距离，并且这些差异会随着物体伸长的增加而增加。相比之下，碎片总是发生在物体的最大半轴上，因此可以通过该半径的球体来建模。碎裂和升华都受到天体物质组成的极大影响，因此也受到其前身小行星带组成的影响。白矮星的温度以及冷却年龄会影响预期的碎片分布：较高的温度会使大型细长小行星升华，