Protoplanetary Propellers in Perturbed Accretion Disks.

扰动吸积盘中的原行星螺旋桨。

• 批准号: 156182056
• 负责人: Professor Dr. Frank Spahn, Ph.D.
• 金额: --
• 依托单位: Institut für Physik und Astronomie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2009
• 资助国家: 德国
• 起止时间: 2008-12-31 至 2015-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/156182056?language=en
• 关键词: Protoplanetary; Propellers; Perturbed; Accretion; Disks.

In this research project we want to extend our scattering-diffusion model, suitable for moonlets in planetary rings, to growing planetary embryos in preplanetary disks. Despite their large differences planetary rings and preplanetary disks share a few essential physical processes justifying this approach and providing the base for this project.Since the detection of extrasolar planets in the middle of the 90ties theories of planet formation have gained a renaissance. The detection of Jovian-like planets very close to the central star has initiated investigations of disk-planet interactions and related migration of protoplanets. Two classes of migrating planets are distinguished: laige gap-inducing planets, and alternatively, small protoplanets unable to clear a gap in the disk.These classes remind closely of moonlets in planetary rings - such as Saturn s Pan and Daphnis creating an empty gap or those carving propeller-like structures in planetary rings as predicted by our models. And indeed, the cameras on the Cassini spacecraft caught a few hundred propellers caused by moonlets with sizes of 50 ... 150 meters! Moreover, a very large propeller pointing to a kilometer-sized moonlet has been found which migrates stochastically.The obvious analogies in both disks provoke the questions: Do non-gap opening planets induce propeller-like structures in preplanetary disks? Under which conditions? Do these planets cause observable modifications of the vertical disk-stratification? What processes can break the symmetry of the propeller-like structures to cause planetary migration? What is the effect of an accreting planetary embryo on the surrounding disk-structure?And finally, the very fact of a migrating moonlet in Saturn s rings provides an ultimate proof for planetary rings being a natural dynamical lab for cosmic disks and also supports the possible importance of an extended scattering-diffusion model for planet formation/migration.

在这个研究项目中，我们希望扩展我们的散射扩散模型，适用于行星环中的小卫星，在行星前盘中生长行星胚胎。尽管行星环和行星盘有很大的不同，但它们有一些共同的基本物理过程，这证明了这种方法的合理性，并为这个项目提供了基础。对非常接近中央星星的类木行星的探测，引发了对盘-行星相互作用和原行星迁移的相关研究。两类迁移行星被区分开来：Laige间隙诱导行星，或者，小的原行星无法清除磁盘中的间隙。这些类让人想起行星环中的小卫星-例如土星的潘和达夫尼创造了一个空的间隙，或者那些雕刻螺旋桨状结构的行星环，正如我们的模型所预测的那样。事实上，卡西尼号飞船上的摄像机捕捉到了几百个由50个小卫星引起的螺旋桨。一百五十米！此外，一个非常大的螺旋桨指向一个更大的小卫星已被发现，迁移stocheros.The明显的类比在两个磁盘挑起的问题：非间隙开放的行星诱导螺旋桨状结构的行星盘？在什么条件下？这些行星会引起垂直盘状分层的可观察到的变化吗？什么过程可以打破螺旋桨状结构的对称性，导致行星迁移？吸积的行星胚胎对周围的盘状结构有什么影响？最后，土星环中迁移小卫星的事实为行星环是宇宙盘的天然动力学实验室提供了最终证据，也支持了扩展的散射扩散模型对行星形成/迁移的可能重要性。