Modelling the secular evolution of protoplanetary disc dust sizes - a comparison between the viscous and magnetic wind case
Modelling the secular evolution of protoplanetary disc dust sizes - a comparison between the viscous and magnetic wind case
复制标题
模拟原行星盘尘埃尺寸的长期演化——粘性风和磁风情况之间的比较
DOI：
10.1093/mnras/stac1461
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发表时间：
2022
影响因子：
4.8
通讯作者：
Zagaria F
中科院分区：
文献类型：
--
作者：
Zagaria F
多年来，人们一直认为原行星盘的演化是粘性的：角动量的重新分配导致吸积和向外扩散。最近，吸积是由于磁风带走角动量的假设获得了新的流行：在这种情况下，预计不会有圆盘扩散。在本文中，我们运行了几个一维气体和尘埃模拟来预测尘埃中圆盘大小的时间演变，以评估它们是否可以用来理解圆盘是如何演变的。我们表明粘性风和磁性风模型具有非常不同的尘盘半径。特别是，磁流体动力风模型是紧凑的，它们的大小要么保持不变，要么随着时间的推移而减小。相反，在粘性情况下（当α > 10−3时），圆盘随着时间的推移而变大。虽然目前的观测缺乏足够的灵敏度来区分这两种情况，但在平均范围内，更高灵敏度的调查可能会对这一目标产生有益的影响。与现有的ALMA （Atacama Large Millimeter/submillimeter Array）波段7数据比较，黏性风和磁性风模型与观测推断的Lupus、Chamaeleon I和Upper Sco尘埃半径都是兼容的。此外，在漂移主导下，Lupus在波段7和波段3中再现了尺寸-光度相关性，而Upper Sco的斜率与预测的数据不同。子结构（可能未被检测到）可以解释一些大尺寸的异常值。更高的角度分辨率观测将有助于在更多光盘的情况下测试我们的预测，这在两个框架中都是预期的，特别是在Upper Sco时代。
For many years, protoplanetary discs have been thought to evolve viscously: angular momentum redistribution leads to accretion and outward disc spreading. Recently, the hypothesis that accretion is due, instead, to angular momentum removal by magnetic winds gained new popularity: no disc spreading is expected in this case. In this paper, we run several 1D gas and dust simulations to make predictions on the time evolution of disc sizesin the dustand to assess whether they can be used to understand how discs evolve. We show that viscous and magnetic wind models have very different dust disc radii. In particular, magnetohydrodynamic wind models are compact and their sizes either remain constant or decrease with time. On the contrary, discs become larger with time in the viscous case (when α ≳ 10−3). Although current observations lack enough sensitivity to discriminate between these two scenarios, higher sensitivity surveys could be fruitful to this goal on aage range. When compared with the available ALMA (Atacama Large Millimeter/submillimeter Array) Band 7 data, both viscous and magnetic wind models are compatible with the observationally inferred dust radii in Lupus, Chamaeleon I, and Upper Sco. Furthermore, in the drift-dominated regime, the size–luminosity correlation is reproduced in Lupus, both in Band 7 and 3, while in Upper Sco a different slope than in the data is predicted. Sub-structures (potentially undetected) can explain several outliers with large observed sizes. Higher angular-resolution observations will be helpful to test our predictions in the case of more compact discs, expected in both frameworks, particularly at the age of Upper Sco.