论文标题
映射TW hya磁盘中的复杂运动学子结构
Mapping the Complex Kinematic Substructure in the TW Hya Disk
论文作者
论文摘要
我们提出了Co $ j = 2-1 $的Alma观察结果,CS $ J = 5-4 $从Tw〜Hydrae周围的磁盘排放。这两个分子都主要追踪开普勒速度结构,尽管在CO发射中检测到旋转速度的减慢速度在磁盘的外边缘的速度放慢速度。这归因于磁盘外边缘附近气体密度锥的增强压力支持。方位角对称背景速度结构的减法揭示了每个分子所追踪的气体运动学中的局部偏差。 CO和CS均表现出“多普勒翻转”功能,几乎沿着磁盘的次要轴($ {\ rm pa} \ sim 60 \ degr $),半径为$ 1 \ farcs35 $,一致,与在散射光和MM continuum中观察到的大缝隙相吻合。此外,通过强度的变化及其运动学的变化,CO的发射迹象是紧密的伤口螺旋,以前具有较高频率的CO $ J = 3-2 $观测值(Teague等,2019)。通过与嵌入式行星产生的螺旋唤醒的线性模型进行比较,我们在与间隙内的土星质量行星相互作用的背景下以$ {\ rm pa} = 60 \ degr $的位置角度的相互作用进行了比较,与(Mentiplay等人的理论预测)一致。 CS发射中缺乏相应的螺旋归因于对浮力螺旋的强垂直依赖性,该浮力被认为仅在磁盘的大气中生长,而不是由CS发射所追踪的。
We present ALMA observations of CO $J = 2-1$ and CS $J = 5-4$ emission from the disk around TW~Hydrae. Both molecules trace a predominantly Keplerian velocity structure, although a slowing of the rotation velocity is detected at the outer edge of the disk beyond ${\approx}~140$~au in CO emission. This was attributed to the enhanced pressure support from the gas density taper near the outer edge of the disk. Subtraction of an azimuthally symmetric background velocity structure reveals localized deviations in the gas kinematics traced by each of the molecules. Both CO and CS exhibit a `Doppler flip' feature, centered nearly along the minor axis of the disk (${\rm PA} \sim 60\degr$) at a radius of $1\farcs35$, coinciding with the large gap observed in scattered light and mm~continuum. In addition, the CO emission, both through changes in intensity and its kinematics, traces a tightly wound spiral, previously seen with higher frequency CO $J = 3-2$ observations (Teague et al., 2019). Through comparison with linear models of the spiral wakes generated by embedded planets, we interpret these features in the context of interactions with a Saturn-mass planet within the gap at a position angle of ${\rm PA} = 60\degr$, consistent with the theoretical predictions of (Mentiplay et al. 2019). The lack of a corresponding spiral in the CS emission is attributed to the strong vertical dependence on the buoyancy spirals which are believed to only grow in the atmospheric of the disk, rather than those traced by CS emission.