论文标题
迁移行星I的气压凹凸处的行星形成。
Planetesimal formation at the gas pressure bump following a migrating planet I. Basic characteristics of the new formation model
论文作者
论文摘要
为了避免行星形成（例如漂移或破碎屏障）的已知困难，已经提出了许多情况。但是，在这种情况下，通常仅在原星盘的某些特定位置形成行星。另一方面，通常在行星形成模型和种群合成模型中假设，行星标志物广泛分布在原星盘中。在这里，我们提出了一种新的方案，可以在该场景中在圆盘的广泛区域形成行星。由第一代行星（例如，由卵石积聚形成）形成的气压凹凸处形成行星，随着行星迁移，地层区域向内扩散。我们使用一个简单的1D拉格朗日粒子模型来计算被迁移的嵌入行星扰动的气盘中卵石的径向分布。我们认为，通过在中间平面上卵石与气体密度比大于统一的点上流动不稳定性，形成了行星。我们还研究了某些关键参数的效果，例如气盘模型的模型，卵石质量通量，行星的迁移速度和湍流强度。我们发现，只要典型的鹅卵石的通量，并且湍流不太强。地球表面密度取决于卵石质量通量和行星的迁移速度。地球区域的总质量和地层区域的轨道位置在很大程度上取决于卵石质量通量。我们还发现，可以通过非常简单的方程式估算地球表面密度及其斜率的轮廓。我们表明，我们的新场景可以解释广泛地区行星的形成。我们为地球表面密度谱提供的简单估计值可用作人群合成模型的初始条件。
To avoid known difficulties in planetesimal formation such as the drift or fragmentation barriers, many scenarios have been proposed. However, in these scenarios, planetesimals form in general only at some specific locations in protoplanetary discs. On the other hand, it is generally assumed in planet formation models and population synthesis models, that planetesimals are broadly distributed in the protoplanetary disc. Here we propose a new scenario in which planetesimals can form in broad areas of the discs. Planetesimals form at the gas pressure bump formed by a first-generation planet (e.g. formed by pebble accretion) and the formation region spreads inward in the disc as the planet migrates. We use a simple 1D Lagrangian particle model to calculate the radial distribution of pebbles in the gas disc perturbed by a migrating embedded planet. We consider that planetesimals form by streaming instability at the points where the pebble-to-gas density ratio on the mid-plane becomes larger than unity. We also study the effect of some key parameters like the ones of the gas disc model, the pebble mass flux, the migration speed of the planet, and the strength of turbulence. We find that planetesimals form in wide areas of the discs provided the flux of pebbles is typical and the turbulence is not too strong. The planetesimal surface density depends on the pebble mass flux and the migration speed of the planet. The total mass of the planetesimals and the orbital position of the formation area depend strongly on the pebble mass flux. We also find that the profile of the planetesimal surface density and its slope can be estimated by very simple equations. We show that our new scenario can explain the formation of planetesimals in broad areas. The simple estimates we provide for the planetesimal surface density profile can be used as initial conditions for population synthesis models.
