Identifying Anticyclonic Vortex Features Produced by the Rossby Wave Instability in Protoplanetary Disks
Identifying Anticyclonic Vortex Features Produced by the Rossby Wave Instability in Protoplanetary Disks
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DOI：
10.3847/1538-4357/aae317
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发表时间：
2018-09
期刊：
影响因子：
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通讯作者：
P. Huang;A. Isella;Hui Li;Shengtai Li;J. Ji
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文献类型：
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作者：
P. Huang;A. Isella;Hui Li;Shengtai Li;J. Ji
附近的几个原行星盘已经被观测到在（亚）毫米尘埃连续辐射中显示出大规模的新月。一种解释是，这些结构对应于反气旋涡所产生的Rossby波不稳定性的气体磁盘。这样的涡旋具有局部的气体超密度，预计会聚集斯托克斯数约为1的尘埃粒子。这个过程可能催化了微行星的形成。虽然最近的观测表明，尘埃新月确实是毫米级颗粒相对于气体和较小颗粒具有异常高浓度的区域，但还没有观测表明新月区域内的气体相对于原行星盘反向旋转。在这里，我们调查的可探测性的反气旋的功能，通过测量的视线分量的气体速度与阿尔马。我们进行了二维流体动力学模拟和三维辐射传输计算的原行星盘的特点是由一个大质量行星的潮汐相互作用产生的漩涡。作为一个案例研究，选择的磁盘参数来模仿IRS 48系统，其中有最突出的新月观察到的日期。我们产生的合成阿尔马观测尘埃连续和12 CO发射的频率为345 GHz左右。我们发现涡旋的反气旋特征很弱，但如果源和观测装置选择得当，可以检测到。我们提供了一个配方，最大限度地提高检测这种涡流功能的概率，并提出了一个分析程序，以推断其运动学特性。
Several nearby protoplanetary disks have been observed to display large-scale crescents in the (sub)millimeter dust continuum emission. One interpretation is that these structures correspond to anticyclonic vortices generated by the Rossby wave instability within the gaseous disk. Such vortices have local gas overdensities and are expected to concentrate dust particles with a Stokes number around unity. This process might catalyze the formation of planetesimals. Whereas recent observations showed that dust crescents are indeed regions where millimeter-size particles have abnormally high concentration relative to the gas and smaller grains, no observations have yet shown that the gas within the crescent region counterrotates with respect to the protoplanetary disk. Here we investigate the detectability of anticyclonic features through measurement of the line-of-sight component of the gas velocity obtained with ALMA. We carry out 2D hydrodynamic simulations and 3D radiative transfer calculations of a protoplanetary disk characterized by a vortex created by the tidal interaction with a massive planet. As a case study, the disk parameters are chosen to mimic the IRS 48 system, which has the most prominent crescent observed to date. We generate synthetic ALMA observations of both the dust continuum and 12CO emission around the frequency of 345 GHz. We find that the anticyclonic features of the vortex are weak but can be detected if both the source and the observational setup are properly chosen. We provide a recipe for maximizing the probability of detecting such vortex features and present an analysis procedure to infer their kinematic properties.