发表机构
Centro de Astrobiología (CAB), CSIC-INTA; Université Lyon 1, ENS de Lyon, CNRS, CRAL; Université Paris-Saclay, Université Paris Cité, CEA, CNRS, AIM; Observatorio Astronómico Nacional (OAN, IGN); Max-Planck-Institut für extraterrestrische Physik（天体生物学中心; 里昂第一大学; 巴黎萨克雷大学; 国家天文台; 马克斯·普朗克地外物理研究所）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
通过核心坍缩模拟，研究了类太阳原恒星中晚期内落气体的起源与物理历史，发现其经磁交换不稳定性形成的丝状结构进入盘，性质类似观测流带，可能改变盘化学组成。
AI 中文摘要
磁流体动力学模拟和针对年轻恒星天体的干涉观测揭示了气体吸积过程，这可能改变原恒星盘的物理性质和化学组成。我们的目标是约束晚期内落气体的物理历史和性质，并评估其改变盘物理和化学性质的潜力。我们进行了质量为5 M$_{\odot}$的气体核心坍缩模拟，其中包含示踪粒子和汇粒子，持续时间约为$3.6\times 10^{5}$年。我们分析了旋转支撑盘的性质，以及最初形成该盘的气体的起源和物理历史。我们还选择了描述晚期内落的示踪粒子，以分析它们的起源和物理历史，并将其与从盘获得的信息进行比较。汇的最终质量达到1.02 M$_\odot$，而盘的质量保持相当恒定，约为0.02 M$_\odot$。在其演化过程中，盘半径增加到约40 au，其密度降低了约8倍。由于磁交换不稳定性的结果，出现了将气体从包层输送到盘和汇的丝状结构。示踪粒子能够识别晚期内落气体，其物理性质类似于观测到的流带（streamers），并且仅在模拟的最后快照中被吸积。晚期内落气体的起源和物理历史与最初形成盘的气体不同。核心坍缩模拟预测了连接包层和盘的丝状结构的出现。通过这些通道的晚期气体吸积具有类似于流带的性质，并将具有不同物理历史的气体带到盘中，这可能转化为不同的化学组成。
英文摘要
Magnetohydrodynamical simulations and interferometric observations toward young stellar objects reveal the accretion of gas that may alter the physical properties and chemical composition of protostellar disks. Our goal is to constrain the physical history and properties of late infalling gas, and assess its potential to change the physical and chemical properties of the disk. We carried out a core collapse simulation of 5 M$_{\odot}$ of gas endowed with tracer and sink particles during $\sim 3.6\times 10^{5}$ yr. We analyzed the properties of the rotationally supported disk, and the origin and physical history of the gas from which it is initially formed. We also selected the tracer particles that describe the late infall to analyze their origin and physical history, and compare them to the information obtained from the disk. The final mass of the sink reaches 1.02 M$_\odot$, while the mass of the disk stays fairly constant around 0.02 M$_\odot$. Throughout its evolution, the disk radius increases up to $\sim 40$ au and its density is reduced by a factor of $\sim 8$. Filaments that channel gas from the envelope to the disk and sink appear as a result of the magnetic interchange instability. Tracer particles can identify late infalling gas, whose physical properties resemble that of observed streamers and are only accreted in the final snapshots of the simulation. The origin and physical history of the late infalling gas are different from those of the gas that initially forms the disk. Core collapse simulations predict the appearance of filaments that connect the envelope to the disk. The late accretion of gas through these channels has properties similar to those of streamers and brings gas to the disk with a different physical history that could translate into a different chemical composition.
Comments12 pages, 9 figures. Accepted for publication in Astronomy and Astrophysics
