论文标题
气流对行星的侵蚀
Erosion of planetesimals by gas flow
论文作者
论文摘要
行星形成的第一阶段发生在主要由气体组成的原星磁盘中。因此，了解气体如何影响原星磁盘中的行星是必不可少的。在本文中，我们讨论气体是否可以侵蚀行星。我们估计，气体随着磁盘和行星特性的函数，将多少剪切应力施加到地球表面上。为了确定是否可以发生侵蚀，我们将其与以前的临界应力测量值进行了比较。如果发生侵蚀，我们将估计受影响的行星的侵蚀时间。我们还使用晶格Boltzmann方法对围绕行星围绕行星的流量进行了二维数值模拟来说明我们的估计值。我们发现，壁剪应力可以克服磁盘最内向区域内偏心轨道中行星的临界应力。达到侵蚀应力所需的高偏心可能是通过迁移行星牧羊的结果。我们还发现，如果行星侵蚀，它会在短时间内进行。对于居住在$ 1 \ \ rm {au} $之外的行星，我们发现它们主要免受侵蚀的保护，即使在高度偏心轨道的情况下也是如此。
The first stages of planet formation take place in protoplanetary disks that are largely made up of gas. Understanding how the gas affects planetesimals in the protoplanetary disk is therefore essential. In this paper, we discuss whether or not gas flow can erode planetesimals. We estimate how much shear stress is exerted onto the planetesimal surface by the gas as a function of disk and planetesimal properties. To determine whether erosion can take place, we compare this with previous measurements of the critical stress that a pebble-pile planetesimal can withstand before erosion begins. If erosion takes place, we estimate the erosion time of the affected planetesimals. We also illustrate our estimates with two-dimensional numerical simulations of flows around planetesimals using the lattice Boltzmann method. We find that the wall shear stress can overcome the critical stress of planetesimals in an eccentric orbit within the innermost regions of the disk. The high eccentricities needed to reach erosive stresses could be the result of shepherding by migrating planets. We also find that if a planetesimal erodes, it does so on short timescales. For planetesimals residing outside of $1 \ \rm{au}$, we find that they are mainly safe from erosion, even in the case of highly eccentric orbits.
