论文标题
同时恒星和行星形成的案例
A case of simultaneous star and planet formation
论文作者
论文摘要
虽然广泛认为行星是在原星磁盘中形成的，但关于这个过程何时发生的辩论仍然存在很多争论。在少数情况下，Protoplanets已直接成像，但是对于绝大多数系统，磁盘间隙和空腔（尤其是在尘埃连续观测中）是最近或正在进行的行星形成的最有力的证据。我们介绍了Alma的观察结果（$ i = 75^{\ circ} $）磁盘，其中包含灰尘中看到的巨大差距，但在$^{12} $ co Gas中却没有。在间隙内部，分子气体具有温暖（100 K）的组分，与VLA观察到的暂定自由发射过量相吻合。使用1D流体动力模型，我们发现差距的结构与由4-70 $ M _ {\ rm jup} $的行星雕刻而成。在行星雕刻的缝隙内部的无自由发射的巧合指向该行星很年轻和/或仍在吸收。此外，$^{12} $ CO的观察结果显示，低速丝状细丝与磁盘的主要轴和速度相干与磁盘气体一致，我们将其解释为我们从本地ISM进行的持续气体输入。该系统似乎是一个有趣的案例，即恒星（来自环境和磁盘）和行星（来自磁盘）都在同时生长。
While it is widely accepted that planets are formed in protoplanetary disks, there is still much debate on when this process happens. In a few cases protoplanets have been directly imaged, but for the vast majority of systems, disk gaps and cavities -- seen especially in dust continuum observations -- have been the strongest evidence of recent or on-going planet formation. We present ALMA observations of a nearly edge-on ($i = 75^{\circ}$) disk containing a giant gap seen in dust but not in $^{12}$CO gas. Inside the gap, the molecular gas has a warm (100 K) component coinciding in position with a tentative free-free emission excess observed with the VLA. Using 1D hydrodynamic models, we find the structure of the gap is consistent with being carved by a planet with 4-70 $M_{\rm Jup}$. The coincidence of free-free emission inside the planet-carved gap points to the planet being very young and/or still accreting. In addition, the $^{12}$CO observations reveal low-velocity large scale filaments aligned with the disk major axis and velocity coherent with the disk gas that we interpret as ongoing gas infall from the local ISM. This system appears to be an interesting case where both a star (from the environment and the disk) and a planet (from the disk) are growing in tandem.
