标题： 磁化恒星凹陷区和内盘中行星迁移的三维MHD模拟 显示英文标题

标题： 3D MHD simulations of planet migration in cavities and inner discs of magnetized stars

摘要： 我们使用全局三维磁流体动力学（MHD）模拟，研究强磁场年轻恒星的低密度空腔和内盘中的行星I型迁移，其中强磁场形成了低密度空腔。 模拟显示，空腔中的行星向内迁移，直到外 Lindblad 共振位于空腔内部的半径。 在更小的半径处，迁移停止。 如果恒星在不稳定的区域吸积，使得临时的舌状结构穿透磁层，迁移会更快。 如果行星处于高度倾斜的轨道上，它会与盘相互作用，由于 Kozai-Lydov 机制，偏心率会增加。 在进入空腔之前，行星可能在内盘中停止或逆转其迁移。 磁层与内盘相互作用，改变其密度分布，从而使迁移减慢甚至逆转。 倾斜的磁层还会在盘中激发密度波和弯曲波，这可能会减缓迁移，并增加行星的倾角和偏心率。 当行星到达盘-空腔边界时，通常会被不对称的共转扭矩困在边界处。 当空腔扩展时，行星会与边界一起移动。 总体而言，磁化恒星为缓慢或逆转的迁移提供了环境。 显示英文摘要

摘要： We investigate the Type I migration of planets in low-density cavities and inner discs of strongly magnetized young stars using global three-dimensional (3D) magnetohydrodynamic (MHD) simulations, where the strong magnetic field carves the low-density cavity. Simulations show that a planet in the cavity migrates inwards up to the radius at which the outer Lindblad resonances are inside the cavity. At smaller radii, the migration stalls. The migration is faster if a star accretes in the unstable regime where the temporary tongues penetrate the magnetosphere. If a planet is in a highly inclined orbit, it interacts with the disc, and the eccentricity increases due to the Kozai-Lydov mechanism. A planet may stop or reverse its migration in the inner disc before entering the cavity. The magnetosphere interacts with the inner disc, changing its density distribution such that migration slows down or is even reversed. A tilted magnetosphere also excites density and bending waves in the disc, which may slow down migration and also increase the inclination and eccentricity of the planet. When a planet reaches the disc-cavity boundary, it is typically trapped at the boundary by asymmetric corotation torque. A planet moves together with the boundary when the cavity expands. Overall, a magnetized star provides an environment for slow or reverse migration.