AI 中文总结
研究跨越恒星质量谱的星子形成，通过一维粘性演化盘模拟结合云坍缩和星子形成的方法，发现其对恒星质量敏感，低质量M矮星周围盘情况特殊，该研究有助于解释系外行星挥发性物质预算及JWST观测现象。
AI 中文摘要
坍缩分子云形成的原行星盘在云坍缩和II类盘阶段都能在水雪线处形成星子。这种情况可能导致太阳系中观测到的碳质/非碳质（CC/NC）异质性，对行星组成有重要意义。我们使用一维粘性演化盘模拟结合云坍缩和星子形成，探索盘形成过程中星子形成如何随恒星质量谱变化。我们发现星子形成的时间、位置和结果对恒星质量非常敏感。所有研究恒星质量的盘在II类阶段都形成星子，但只有低质量M矮星（$M_{\star}=0.1 M_{\odot}$）周围的盘在吸积阶段不形成。在$M_{\rm{cloud}} \geq 0.3M_{\odot}$云形成的盘中，星子群体也存在明显的化学异质性（湿水和干）。低质量M矮星周围的盘形成并经历极快的卵石漂移（t < 2 Myr），在铝-26半衰期内形成星子。这导致所有考虑的M矮星盘形成情况下的星子脱水。我们认为盘演化随恒星质量的变化使得难以确定所有盘的共同t = 0，并且低质量M矮星周围脱水星子形成的系外行星将贫挥发性物质诞生——这可能解释了JWST观测到的岩石世界大气的缺乏。
英文摘要
Protoplanetary discs emerging from collapsing molecular clouds are capable of forming planetesimals at the water snowline during both the cloud collapse and Class II disc phases; such a scenario could be responsible for creating the carbonaceous/non-carbonaceous (CC/NC) heterogeneity observed in the Solar System, and bears important implications for emergent planetary compositions. We use 1D simulations of a viscously evolving disc coupled with cloud collapse and planetesimal formation to explore how planetesimal formation during disc build-up varies across the stellar mass spectrum. We find a keen sensitivity of planetesimal formation timing, location, and outcomes on stellar mass. Discs around all investigated stellar masses form planetesimals in the Class II phase, but only the disc around low-mass M-dwarfs ($M_{\star}=0.1 M_{\odot}$) fails to form them during the infall phase. There is also a clear chemical heterogeneity in planetesimal populations (water-wet and dry) in discs born from clouds of $M_{\rm{cloud}} \geq 0.3M_{\odot}$ . Discs around low-mass M-dwarfs form and undergo extremely fast pebble drift (t < 2 Myr), forming planetesimals well within the half-life of Aluminium-26. This leads to dehydrated planetesimals in all M-dwarf disc formation cases considered. We argue that the variation in disc evolution across stellar mass makes it hard to pinpoint a common t = 0 for all discs, and that exoplanets emerging from dehydrated planetesimals around low-mass M-dwarfs will be born volatile-poor - potentially explaining the lack of rocky world atmospheres seen by JWST.
Comments15 pages, 9 figures; accepted for publication in MNRAS
Journal refMon Not R Astron Soc (2026)
