Formation of close-in super-Earths in evolving protoplanetary disks due to disk winds
Formation of close-in super-Earths in evolving protoplanetary disks due to disk winds
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DOI：
10.1051/0004-6361/201832720
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发表时间：
2018-04
影响因子：
6.5
通讯作者：
M. Ogihara;E. Kokubo;T. Suzuki;A. Morbidelli
中科院分区：
文献类型：
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作者：
M. Ogihara;E. Kokubo;T. Suzuki;A. Morbidelli
上下文质量大于0.1 M的行星在标准的原行星盘中经历快速向内迁移（I型迁移）。最近的磁流体动力学模拟揭示了磁驱动盘风的存在，这将改变磁盘的配置文件和I型迁移在近距离区域。目标。我们研究了在盘风影响下粘性演化的盘中行星胚胎的轨道演化。目的是讨论改变磁盘配置文件的影响，I型迁移。此外，我们的目标是研究是否可以通过模拟，包括磁盘风的影响，复制观察到的分布接近超级地球。方法.我们对超级地球从行星胚胎形成进行了N体模拟，其中使用了最近的磁盘演化模型。我们探索了广泛的参数并得出了总体趋势。我们还进行了N体模拟的近距离超级地球形成的胚胎在这样的磁盘在各种条件下。结果我们发现，在许多情况下，I型迁移显着抑制。即使在发生向内迁移的情况下，迁移的时间尺度也延长到100万年，这减轻了第一类迁移问题。这是因为气体表面密度降低，并且由于盘风而在接近区域中具有更平坦的轮廓。我们发现，当I型迁移被显着抑制，行星经历后期轨道不稳定性期间的气体耗尽，导致非共振配置。我们还发现，观测到的近距离超级地球的分布（例如，周期比、质量比）。此外，我们表明，在一些结果的模拟，系统与链的共振行星，如TRAPPIST-1系统，形成。
Context. Planets with masses larger than about 0.1 M⊕ undergo rapid inward migration (type I migration) in a standard protoplanetary disk. Recent magnetohydrodynamical simulations revealed the presence of magnetically driven disk winds, which would alter the disk profile and the type I migration in the close-in region. Aims. We investigate orbital evolution of planetary embryos in disks that viscously evolve under the effects of disk winds. The aim is to discuss effects of altered disk profiles on type I migration. In addition, we aim to examine whether observed distributions of close-in super-Earths can be reproduced by simulations that include effects of disk winds. Methods. We perform N-body simulations of super-Earth formation from planetary embryos, in which a recent model for disk evolution is used. We explore a wide range of parameters and draw general trends. We also carry out N-body simulations of close-in super-Earth formation from embryos in such disks under various conditions. Results. We find that the type I migration is significantly suppressed in many cases. Even in cases in which inward migration occurs, the migration timescale is lengthened to 1 Myr, which mitigates the type I migration problem. This is because the gas surface density is decreased and has a flatter profile in the close-in region due to disk winds. We find that when the type I migration is significantly suppressed, planets undergo late orbital instability during the gas depletion, leading to a non-resonant configuration. We also find that observed distributions of close-in super-Earths (e.g., period ratio, mass ratio) can be reproduced. In addition, we show that in some results of simulations, systems with a chain of resonant planets, like the TRAPPIST-1 system, form.