CO Line Emission Surfaces and Vertical Structure in Midinclination Protoplanetary Disks
CO Line Emission Surfaces and Vertical Structure in Midinclination Protoplanetary Disks
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DOI：
10.3847/1538-4357/ac6c02
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发表时间：
2022-05
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通讯作者：
C. Law;Sage Crystian;R. Teague;K. Öberg;Evan A. Rich;S. Andrews;J. Bae;K. Flaherty;V. Guzmán;Jane Huang;J. Ilee;J. Kastner;R. Loomis;F. Long;L. P'erez;S. Pérez;C. Qi;G. Rosotti;D. Ruíz-Rodríguez;T. Tsukagoshi;D. Wilner
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作者：
C. Law;Sage Crystian;R. Teague;K. Öberg;Evan A. Rich;S. Andrews;J. Bae;K. Flaherty;V. Guzmán;Jane Huang;J. Ilee;J. Kastner;R. Loomis;F. Long;L. P'erez;S. Pérez;C. Qi;G. Rosotti;D. Ruíz-Rodríguez;T. Tsukagoshi;D. Wilner
中倾角（φ 30° ~ 75 °）原行星盘的高空间分辨率CO观测为研究CO排放和温度的垂直分布提供了机会。线发射相对于盘主轴的不对称性允许在中平面上方的发射高度的直接映射，并且对于LTE中的光学厚的空间分辨发射，强度是局部气体温度的量度。我们的分析阿塔卡马大型毫米/亚毫米阵列档案数据产生CO发射表面，动态约束恒星主机质量，和磁盘周围的磁盘大气气体温度：HD 142666，MY Lup，V4046 Sgr，HD 100546，GW Lup，WaOph 6，DoAr 25，Sz 91，CI Tau和DM Tau。这些来源的恒星质量（0.50-2.10 M），年龄（0.3-23百万年）和CO气体径向发射范围（200-1000 Au）范围很广。这个样本几乎是具有映射发射表面的盘的数量的三倍，并且证实了在先前的研究中暗示的线发射高度（z/r = 0.1至0.5）的广泛多样性。我们计算每个圆盘的径向和垂直CO气体温度分布。少数圆盘显示局部温度下降或增强，其中一些对应于尘埃子结构或嵌入行星的建议位置。几个发射表面也显示出垂直的子结构，它们都与毫米尘埃中的环和间隙对齐。结合我们的样本与文献来源，我们发现，CO线发射的高度弱下降与恒星质量和气体温度，尽管大的散射，是符合简单的标度关系。我们还观察到CO排放高度和磁盘大小之间的相关性，这是由于耀斑结构的磁盘。总的来说，CO排放表面跟踪102 -5×气体压力标度高度（Hg），并可能被校准为汞的经验示踪剂。
High spatial resolution CO observations of midinclination (≈30°–75°) protoplanetary disks offer an opportunity to study the vertical distribution of CO emission and temperature. The asymmetry of line emission relative to the disk major axis allows for a direct mapping of the emission height above the midplane, and for optically thick, spatially resolved emission in LTE, the intensity is a measure of the local gas temperature. Our analysis of Atacama Large Millimeter/submillimeter Array archival data yields CO emission surfaces, dynamically constrained stellar host masses, and disk atmosphere gas temperatures for the disks around the following: HD 142666, MY Lup, V4046 Sgr, HD 100546, GW Lup, WaOph 6, DoAr 25, Sz 91, CI Tau, and DM Tau. These sources span a wide range in stellar masses (0.50–2.10 M ⊙), ages (∼0.3–23 Myr), and CO gas radial emission extents (≈200–1000 au). This sample nearly triples the number of disks with mapped emission surfaces and confirms the wide diversity in line emitting heights (z/r ≈ 0.1 to ≳0.5) hinted at in previous studies. We compute the radial and vertical CO gas temperature distributions for each disk. A few disks show local temperature dips or enhancements, some of which correspond to dust substructures or the proposed locations of embedded planets. Several emission surfaces also show vertical substructures, which all align with rings and gaps in the millimeter dust. Combining our sample with literature sources, we find that CO line emitting heights weakly decline with stellar mass and gas temperature, which, despite large scatter, is consistent with simple scaling relations. We also observe a correlation between CO emission height and disk size, which is due to the flared structure of disks. Overall, CO emission surfaces trace ≈2–5× gas pressure scale heights (Hg) and could potentially be calibrated as empirical tracers of Hg.