Tidal stimulation of the formation of the outer planets

行星形成是当前天文学和天体物理学中的一个关键问题，因此，它一直是争论的焦点。越来越多的太阳系外行星系统观测数据不断挑战理论模型。虽然尘埃形成行星体的基本机制以及行星体形成原行星的许多细节仍不清楚，但越来越多的证据表明，像我们这样的行星系统存在密集的动态诞生环境。在强烈偏心和/或错位的轨道上发现的系外行星表明，形成行星系统的动力学比之前认为的更加复杂。即使是我们的太阳也显示出7度西经时的适度错位。黄道面，并且，除了八颗规则的行星外，我们的太阳系还拥有各种遥远和偏心轨道上的小行星(例如Sedna)。它们的起源对当前的行星形成理论提出了挑战。我在此申请的这个项目的重点是试图通过一个很少有人关注的原行星盘的潮汐扰动和富含气体的恒星形成环境中的物质交换的场景来理解我们太阳系的这些特殊特征，这可能在埃奇沃斯-柯伊伯带的形成中发挥了重要作用。特别是，将分析由诞生星团中经过的恒星所产生的潮汐力量或来自恒星形成区内致密结构的气体流入所引起的瞬变涡旋，以及这些涡旋内加强尘埃凝结的可能性。此外，还将研究由盘状扰动引起的反复吸积对太阳化学的影响，特别是观测到的锂的贫化。据我所知，没有其他研究小组致力于这个环境驱动的ANSAZ来解释太阳系的特殊特征。

Planet formation is a key issue in current astronomy and astrophysics, and as such it is subject to ongoing debates. An increasing amount of observational data on extrasolar planetary systems repeatedly challenges theoretical models. While many details on the basic mechanisms of forming planetesimals from dust and protoplanets from planetesimals are still unclear, there is increasing evidence for fingerprints of a dense dynamical birth environment of planetary systems like ours. The discoveries of exoplanets on strongly eccentric and/or misaligned orbits suggest even more complex dynamics in forming planetary systems than previously thought. Even our Sun exhibits a modest misalignment of 7degree wrt. the ecliptic plane, and, besides the eight regular planets, our Solar Systems also hosts a variety of minor planets on distant and eccentric orbits (e.g. Sedna). Their origin poses a challenge to current planet formation theory. The project which I am herewith applying for focuses on an attempt to understand these peculiar features of our Solar System through a yet rarely attended scenario of tidal perturbations of protoplanetary discs and material exchange in gas-rich star-forming environments, which may have played an important role in the formation of the Edgeworth-Kuiper Belt. In particular, transient vortices caused by the tidal forces by passing stars in the birth cluster or by the inflow of gas from dense structures inside the star-forming region and the possibility of enhanced dust coagulation inside these vortices will be analysed. In addition, the consequences of repeated accretion due to disc perturbations on the Solar chemistry, particularly the observed Lithium depletion, will be studied. To my knowledge no other group is working on this environment-driven ansatz to explain the peculiar features of the Solar System.