arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2606.02457astro-ph.EPastro-ph.SR
收藏

白矮星周围潮汐碎屑的尺寸限制：千米级屏障

Size limits on tidal debris around white dwarfs: the km-size barrier

University of Texas at Austin（德克萨斯大学奥斯汀分校）；Planetary Science Institute（行星科学研究所）；University of Warwick（华威大学）

Jordan K. Steckloff, Dimitri Veras, Kathryn Volk

备注：
11 pages. Accepted for Publication
阅读 PDF
arXiv 页面 ↗HTML 原文 ↗

AI总结：

本文通过考虑范德瓦尔斯力引起的非零内聚力，计算了白矮星周围潮汐碎裂产生的最大碎片尺寸，发现典型尺寸为0.1-1千米，即千米级屏障，并指出后续盘演化需先经历碰撞研磨等尘埃形成过程。

摘要：

围绕白矮星运行的致密行星碎片盘为我们理解演化后的行星系统提供了重要窗口。这些盘的形成已被广泛建模为小行星（无内聚强度的碎石堆）的潮汐碎裂。然而，碎石堆由于范德瓦尔斯力确实具有非零内聚强度，这里我们展示了其后果：这些碎石堆的碎裂设定了最大碎片尺寸，我们计算了水冰、铁以及对应于月球高地、灶神星和地球的物质密度下的这一尺寸。我们发现，对于典型的最小碎石堆强度$\sim$10-1000 Pa，最大碎片尺寸可达小行星大小（0.1-1千米）。这一限制——千米级屏障——也代表了潮汐碎片的特征尺寸。大部分碎片质量包含在此尺寸的碎片中。因此，后续的盘演化应首先出现显著的尘埃形成过程，如碰撞研磨，然后波因廷-罗伯逊阻力才能显著塑造最终的盘。此外，我们发现非零内聚力比无强度情况更窄地径向约束碎片。这一对先前假设的修正增加了碰撞在白矮星碎片盘形成和演化中重要性的日益增长的证据，同时也帮助限制了这些盘中用于建模的尺寸分布。

英文摘要：

Compact disks of planetary debris orbiting white dwarfs provide a crucial window into our understanding of evolved planetary systems. The formation of these disks has been widely modeled with tidal fragmentation of minor planets that are rubble piles with no internal strength. However, rubble piles do have non-zero cohesive strength from Van der Waals forces, and here we demonstrate the consequences: breakup of these rubble piles sets a maximum fragment size, and we calculate this size \jks{for water ice, iron, and material densities corresponding to the lunar highlands, Vesta and the Earth}. We find that for typical minimum rubble pile strengths of $\sim$10-1000 Pa, the maximum fragment size is as large as small asteroids (0.1-1 km). This limit -- the km-size barrier -- also represents the characteristic sizes of tidal fragments. Most of the debris mass is contained in fragments of this size. Consequently, subsequent disk evolution should first feature a prominent dust-forming process, such as collisional grinding, before Poynting-Robertson drag can significantly shape the final disk. \jks{Further, we find that non-zero internal strength more narrowly radially confines the fragments than in the strengthless case.} This correction to previous assumptions adds to the growing evidence of the importance of collisions in the formation and evolution of white dwarf debris disks, while also helping to bound the size distribution in these disks for modeling efforts.

机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。

↑