发表机构
School of Mathematical and Physical Sciences, Macquarie University; School of Physics and Astronomy, Monash University（麦考瑞大学数理科学学院; 蒙纳士大学物理与天文学院）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究检验后AGB星盘中核吸积框架下的行星形成各阶段，发现尘埃凝聚可行，高盘质量下星子可快速卵石吸积达隔离质量，理论上第二代行星形成可行。
AI 中文摘要
观测已证实，后渐近巨分支（post-AGB）双星周围形成的环双星盘与年轻恒星周围的原行星盘具有惊人的相似性。在本研究中，我们检验了后AGB星盘中行星形成的核吸积框架内不同生长阶段的可行性，以评估在这些系统中行星形成是否可能。我们发现，尘埃凝聚至毫米级大小在后AGB星盘的寿命内是可能的，这与观测一致。随后，我们研究了通过卵石和星子吸积进行的星子后续生长。如果流不稳定性在这些星盘中起作用，则在质量较高的后AGB星盘（$M_{\rm disc}\sim0.1M_\odot$）中形成的星子可以进入快速卵石吸积阶段，并在估计的星盘寿命内达到其隔离质量。相比之下，在质量较低的后AGB星盘（$M_{\rm disc}\sim0.01M_\odot$）中，星子吸积效率过低，无法产生显著的进一步生长。我们还表明，与年轻恒星周围的原行星盘相比，后AGB星盘较大的纵横比意味着较高的卵石隔离质量，因此可能形成质量高达木星质量的岩石行星。在评估了这些星盘中的气体吸积和伴随迁移后，我们得出结论：在后AGB星盘中，第二代行星形成在其估计的寿命（$10^4$--$10^5$年）内理论上可行，前提是实现了局部的尘埃与气体比增强以及足够高的星盘质量。
英文摘要
Observations have established that the circumbinary discs formed around post-asymptotic giant branch (post-AGB) binaries have striking similarities to protoplanetary discs around young stars. In this study, we examine the feasibility of the different stages of growth in the core accretion framework of planet formation in post-AGB discs, in order to assess whether planet formation is possible in these systems. We find that dust coagulation up to mm sizes is possible within the lifetimes of post-AGB discs, consistent with observations. We then investigate the subsequent growth of planetesimals through pebble and planetesimal accretion. If the streaming instability operates in these discs, the resulting planetesimals formed in higher-mass post-AGB discs ($M_{\rm disc}\sim0.1M_\odot$) can enter rapid pebble accretion and reach their isolation mass within the estimated disc lifetime. By contrast, in lower-mass post-AGB discs ($M_{\rm disc}\sim0.01M_\odot$), planetesimal accretion is too inefficient to produce substantial further growth. We also show that the larger aspect ratios of post-AGB discs compared to protoplanetary discs around young stars imply high pebble isolation masses and therefore potential formation of rocky planets with masses extending up to Jupiter masses. After assessing gas accretion and concurrent migration in these discs, we conclude that second generation planet formation in post-AGB discs is theoretically possible within their estimated lifetimes ($10^4$--$10^5$yr) provided that local dust-to-gas ratio enhancements and sufficiently high disc masses are achieved.
