AI 中文总结
研究行星形成盘角动量，通过计算15个盘角动量并推导相关关系估计另外18个盘角动量，与理论预测比较，发现多数盘角动量低，后期吸积物质与附近云团相互作用或可解释盘与行星系统不对准。
AI 中文摘要
背景。相当一部分（>30%）行星形成盘和行星与其主恒星的自转轴不对准，但其主导机制仍不清楚。目的。我们旨在通过观测限制II类原行星盘的角动量，并评估后期物质吸积是否能带来足够角动量使其倾斜。方法。我们首先计算了15个盘的角动量，其表面密度分布由高角分辨率ALMA观测的动力学模型推断得出。基于此样本，我们得出了盘角动量与恒星质量、盘质量以及包含90% 13CO通量的半径之间的关系，并用于估计另外18个盘的角动量。然后将盘的值与来自云团后期吸积和观测到的条带的理论预测进行比较。结果。大多数盘的角动量低于理论模型对后期吸积的预测。这在定性上也与条带观测结果一致，不过需要对供应条带的物质储存库的质量进行表征来证实这一情况。结论。与附近云团的相互作用导致物质后期落入II类盘，这可能解释了在盘和行星系统中观测到的不对准现象。
英文摘要
Context. A significant fraction (>30%) of planet-forming disks and planetary are misaligned with respect to the rotational axis of their host stars, yet the dominant mechanism responsible for these misalignments remains unclear. Aims. We aim to observationally constrain the angular momentum of Class II protoplanetary disks and assess whether late-stage infall of material can bring sufficient angular momentum to tilt them. Methods. We first computed the angular momenta of 15 disks with surface density profiles inferred from dynamical modeling of high angular resolution ALMA observations. Based on this sample, we derived a relation linking disk angular momentum to stellar mass, disk mass, and the radius enclosing 90% of the 13CO flux and used it to estimate angular momenta of 18 more disks. We then compared disk values with theoretical predictions for late-stage accretion from clouds and observed streamers. Results. Angular momentum for most disks is lower than what theoretical models predict for late infall. This is also in qualitative agreement with comparison with streamer observations, however, characterization of mass of reservoirs feeding the streamers is needed to confirm this picture. Conclusions. Interactions with nearby clouds, resulting in late-stage infall of material onto Class II disks, can potentially explain the observed misalignments within disks and planetary systems.
CommentsAccepted in A&A
