发表机构
University of Michigan; California Institute of Technology（密歇根大学; 加州理工学院）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本文提出行星碰撞在AGB星向白矮星转变时产生厘米级岩石碎片，并经坡印廷-罗伯逊阻力演化，为白矮星污染提供新途径。
AI 中文摘要
本文探讨了白矮星周围碎片盘的产生，这些白矮星被观测到频繁发生污染事件。在该情景中，行星碰撞发生在一颗高度演化的AGB星表面之外，在其质量损失阶段结束之后，当它开始向白矮星转变之时。碰撞使一部分行星物质汽化，随后这些物质膨胀、冷却、成核形成液滴，并凝结成特征尺寸约为$s\sim1$厘米的岩石天体。岩石碎片盘通过坡印廷-罗伯逊阻力的作用演化，该阻力由恒星光度驱动，恒星光度起初很大但随时间稳定下降。这一情景为将岩石物质输送到白矮星附近区域提供了另一条途径。
英文摘要
This paper explores the production of debris disks around white dwarfs, which are observed to experience frequent pollution events. In this scenario, planetary collisions occur just outside the surface of a highly evolved AGB star, after the end of its mass loss phase, as it starts its transition into a white dwarf. The collisions vaporize a fraction of the planetary material, which subsequently expands, cools, nucleates droplets, and condenses into rocky bodies with characteristic size of order $s\sim1$ cm. The rocky debris disk evolves through the action of Poynting-Robertson drag, driven by the stellar luminosity, which is initially large but steadily decreases with time. This scenario provides an alternate channel for delivering rocky material to the immediate vicinity of a white dwarf.
Comments44 pages, 7 figures, accepted for publication in PASP
