高角分辨率盘亚结构计划（DSHARP）：VIII。AS 209盘的丰富环状子结构
Disk Substructures at High Angular Resolution Program (DSHARP): VIII. The Rich Ringed Substructures in the AS 209 Disk
摘要：
本文详细分析了高角分辨率（0。037，相当于5天文单位）观测的1.25毫米连续谱和$^{12}$ CO $2-1$发射从磁盘周围的金牛座T星AS 209。AS 209拥有DSHARP样本中最不寻常的磁盘之一，第一次高角分辨率ALMA磁盘调查（Andrews et al. 2018），因为几乎所有的发射都可以用同心高斯环来解释。特别是，尘埃排放由一系列狭窄和紧密间隔的环在内部$\sim$ 60 au，两个分离良好的明亮的环在外盘，集中在74和120 au，和至少两个较暗的发射功能，在90和130 au。我们模拟的videlion与径向表面亮度分布的参数表示，由一个中央核心和7个同心高斯环。最近对低粘度盘的流体动力学模拟表明，超级地球行星可以产生AS 209毫米连续辐射中看到的多个间隙。$^{12}$ CO谱线的发射在中心达到峰值，并延伸到$\sim$ 300 au，比毫米尘埃发射远得多。我们发现轴对称的，本地化赤字的CO排放周围四个不同的半径，近45，75，120和210金。最外面的间隙位于毫米粉尘排放的边缘之外，因此不能归因于粉尘不透明性，而必须由真正的CO表面密度降低引起，由于化学效应或总气体含量的耗尽。
英文摘要：
We present a detailed analysis of the high-angular resolution (0.''037, corresponding to 5 au) observations of the 1.25 mm continuum and $^{12}$CO $2-1$ emission from the disk around the T Tauri star AS 209. AS 209 hosts one of the most unusual disks from the DSHARP sample, the first high angular resolution ALMA survey of disks (Andrews et al. 2018), as nearly all of the emission can be explained with concentric Gaussian rings. In particular, the dust emission consists of a series of narrow and closely spaced rings in the inner $\sim$60 au, two well-separated bright rings in the outer disk, centered at 74 and 120 au, and at least two fainter emission features at 90 and 130 au. We model the visibilities with a parametric representation of the radial surface brightness profile, consisting of a central core and 7 concentric Gaussian rings. Recent hydro-dynamical simulations of low viscosity disks show that super-Earth planets can produce the multiple gaps seen in AS 209 millimeter continuum emission. The $^{12}$CO line emission is centrally peaked and extends out to $\sim$300 au, much farther than the millimeter dust emission. We find axisymmetric, localized deficits of CO emission around four distinct radii, near 45, 75, 120 and 210 au. The outermost gap is located well beyond the edge of the millimeter dust emission, and therefore cannot be due to dust opacity and must be caused by a genuine CO surface density reduction, due either to chemical effects or depletion of the overall gas content.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
