论文标题
迁移模型和热扭矩对卵石积分情景中行星生长的影响
Influence of migration models and thermal torque on planetary growth in the pebble accretion scenario
论文作者
论文摘要
在原星盘内生长更大的低质量行星与磁盘交换扭矩并相应地更改其半高轴。此过程称为I型迁移，并且很大程度上取决于基础磁盘结构。结果，关于行星迁移的一般不确定性。在许多模拟中，当前的I型迁移速率导致行星在磁盘寿命内到达磁盘的内边缘。热扭矩之间的一种新型的扭矩交换，旨在通过加热扭矩减慢向内迁移。如果行星光度足够大，加热扭矩甚至可能导致行星向外迁移。在这里，我们研究了先前I型模型之上热扭矩的行星迁移的影响。我们发现Paardekooper等人的公式。 （2011年）在大多数配置中，与Jiménez＆Masset（2017）（2017）相比，外向迁移更多，但我们还发现，在单个行星形式的情况下，使用这两个公式，包括卵石和气体积聚，使用这两个公式都会演变为非常相似的质量和最终轨道半径。如果添加热扭矩可以引入新的，但很小的向外迁移区域，如果对行星的积聚速率对应于卵石积聚场景之后的典型实心积聚率。如果对行星上的积聚速率变得非常大，那么在具有较大的卵石通量（例如，高金属度环境）的环境中可能会如此，则热扭矩可以使更有效的向外迁移。但是，即使到那时，我们星球地层中最终质量和轨道位置的变化也很小。这意味着对于单个行星的演变情景，加热扭矩的影响可能可以忽略不计。
Low-mass planets that are in the process of growing larger within protoplanetary disks exchange torques with the disk and change their semi-major axis accordingly. This process is called type I migration and is strongly dependent on the underlying disk structure. As a result, there are many uncertainties about planetary migration in general. In a number of simulations, the current type I migration rates lead to planets reaching the inner edge of the disk within the disk lifetime. A new kind of torque exchange between planet and disk, the thermal torque, aims to slow down inward migration via the heating torque. The heating torque may even cause planets to migrate outwards, if the planetary luminosity is large enough. Here, we study the influence on planetary migration of the thermal torque on top of previous type I models. We find that the formula of Paardekooper et al. (2011) allows for more outward migration than that of Jiménez & Masset (2017) in most configurations, but we also find that planets evolve to very similar mass and final orbital radius using both formulae in a single planet-formation scenario, including pebble and gas accretion. Adding the thermal torque can introduce new, but small, regions of outwards migration if the accretion rates onto the planet correspond to typical solid accretion rates following the pebble accretion scenario. If the accretion rates onto the planets become very large, as could be the case in environments with large pebble fluxes (e.g., high-metallicity environments), the thermal torque can allow more efficient outward migration. However, even then, the changes for the final mass and orbital positions in our planet formation scenario are quite small. This implies that for single planet evolution scenarios, the influence of the heating torque is probably negligible.
