论文标题
流媒体不稳定性的非线性演变在积聚原星磁盘中
Nonlinear evolution of streaming instabilities in accreting protoplanetary disks
论文作者
论文摘要
流媒体不稳定性（SI）是通过产生经历重力崩溃的密集的灰尘结块来触发行星形成的最有希望的候选者之一。因此，了解SI在现实的原星盘（PPD）中的运作方式对于评估行星形成的效率至关重要。 PPD的现代型号表明，大型磁性扭矩或风可以驱动磁盘中平面附近的层流气体积聚。在先前的研究中，我们确定了一种新的线性尘埃气流不稳定性，方位角漂移SI（ADSI），适用于这种吸收磁盘，并由粉尘和气体之间的相对方位运动动力供电，这是由于气体被扭转而导致的。在这项工作中，我们介绍了ADSI的第一个非线性模拟。我们表明，即使没有全球径向压力梯度，它也可能会破坏积聚，尘土飞扬的磁盘，这与经典的SI不同。我们发现ADSI驱动了湍流以及经历合并的垂直延伸的灰尘丝的形成。在灰尘圆盘中，合并后的ADSI丝达到了超过100的最大灰尘与气体比。此外，我们发现，即使在尘埃盘中，ADSI也可以将局部灰尘密度提高两个数量级。我们讨论了ADSI在行星形成中的可能作用，尤其是在带有径向压力梯度消失的PPD区域中。
The streaming instability (SI) is one of the most promising candidates for triggering planetesimal formation by producing dense dust clumps that undergo gravitational collapse. Understanding how the SI operates in realistic protoplanetary disks (PPDs) is therefore crucial to assess the efficiency of planetesimal formation. Modern models of PPDs show that large-scale magnetic torques or winds can drive laminar gas accretion near the disk midplane. In a previous study, we identified a new linear dust-gas instability, the azimuthal drift SI (AdSI), applicable to such accreting disks and is powered by the relative azimuthal motion between dust and gas that results from the gas being torqued. In this work, we present the first nonlinear simulations of the AdSI. We show that it can destabilize an accreting, dusty disk even in the absence of a global radial pressure gradient, which is unlike the classic SI. We find the AdSI drives turbulence and the formation of vertically-extended dust filaments that undergo merging. In dust-rich disks, merged AdSI filaments reach maximum dust-to-gas ratios exceeding 100. Moreover, we find that even in dust-poor disks the AdSI can increase local dust densities by two orders of magnitude. We discuss the possible role of the AdSI in planetesimal formation, especially in regions of an accreting PPD with vanishing radial pressure gradients.
