论文标题
多孔粉尘晶粒在原星盘中的演变 - I.生长谷物
Evolution of porous dust grains in protoplanetary discs -- I. Growing grains
论文作者
论文摘要
行星形成的主要问题之一，阻碍了小尘到行星的生长，是所谓的径向拖式屏障。 CM到DM尺寸的鹅卵石被认为在原月经碟片上径向漂移速度比它们生长到更大的尺寸，从而丢失到恒星。为了克服这一障碍，必须放慢或停止漂移，或者需要加快生长。在本文中，我们研究了孔隙度在漂移和生长生长中的作用。我们已经开发了一个在晶粒生长过程中孔隙率演变的模型，并将其应用于原球盘的数值模拟。我们发现多孔谷物的生长速度更快，使它们能够过渡到斯托克斯阻力状态，从气体中解散并在径向拖式屏障中生存。在圆盘的大面积上，可能会直接形成多孔灰尘的小行星。
One of the main problems in planet formation, hampering the growth of small dust to planetesimals, is the so-called radial-drift barrier. Pebbles of cm to dm sizes are thought to drift radially across protoplanetary discs faster than they can grow to larger sizes, and thus to be lost to the star. To overcome this barrier, drift has to be slowed down or stopped, or growth needs to be sped up. In this paper, we investigate the role of porosity on both drift and growth. We have developed a model for porosity evolution during grain growth and applied it to numerical simulations of protoplanetary discs. We find that growth is faster for porous grains, enabling them to transition to the Stokes drag regime, decouple from the gas, and survive the radial-drift barrier. Direct formation of small planetesimals from porous dust is possible over large areas of the disc.
