论文标题
卵石中的“无饮用”卵石堆积在原月光磁盘中，中平面湍流随半径增加而增加
A "no-drift" runaway pile-up of pebbles in protoplanetary disks in which midplane turbulence increases with radius
论文作者
论文摘要
行星形成的一个显着挑战是找到直接从小颗粒形成行星的路径。我们的目标是了解浮雕如何在具有不均匀湍流结构的原星盘中堆积。我们考虑了一个磁盘结构，其中平面湍流粘度随着静物磁盘的半径而增加，就像死区的外部区域一样。我们对鹅卵石进行1D扩散 - 添加模拟，其中包括后反应（惯性）到径向漂移以及给定的卵石至气体质量液体的卵石的垂直/径向/径向扩散。我们报告了一种新的机制，即“无饮用”失控的堆积，导致圆盘中的卵石积聚，因此有利于通过流和/或重力不稳定性形成行星。当卵石从外盘从外盘飘进并进入死区时，就会发生这种情况。然后，卵石细胞的尺度高度降低，对于死亡区域中湍流的足够小值以及卵石与气体磁通量的高值，卵石在气体上的后反应会导致其漂移速度显着降低，从而导致其渐进积累。当卵石的通量与气体的通量之比足够大时，就会发生这种情况，以使效果占主导地位在任何kelvin-helmholtz剪切不稳定性上。这个过程与压降的存在无关。
A notable challenge of planet formation is to find a path to directly form planetesimals from small particles. We aim to understand how drifting pebbles pile up in a protoplanetary disk with a non-uniform turbulence structure. We consider a disk structure in which the midplane turbulence viscosity is increasing with radius in protoplanetary disks as in the outer region of a dead zone. We perform 1D diffusion-advection simulations of pebbles that include back-reaction (the inertia) to radial drift and vertical/radial diffusion of pebbles for a given pebble-to-gas mass flux. We report a new mechanism, the "no-drift" runaway pile-up, leading to a runaway accumulation of pebbles in disks, thus favoring the formation of planetesimals by streaming and/or gravitational instabilities. This occurs when pebbles drifting in from the outer disk and entering a dead zone experience a decrease in vertical turbulence. The scale height of the pebble subdisk then decreases, and for small enough values of the turbulence in the dead zone and high values of the pebble to gas flux ratio, the back-reaction of pebbles on gas leads to a significant decrease in their drift velocity and thus their progressive accumulation. This occurs when the ratio of the flux of pebbles to that of the gas is large enough so that the effect dominates over any Kelvin-Helmholtz shear instability. This process is independent of the existence of a pressure bump.
