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arXiv 0910.1004astro-ph.EP
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巨行星的远距离向外迁移及其对北落师门b的应用

Long range outward migration of giant planets, with application to Fomalhaut b

A. Crida, F. Masset, A. Morbidelli

摘要:

最近通过直接成像对系外行星的观测表明,巨行星的轨道距离其中心恒星几十到一百多个AU。这些行星的起源问题挑战了行星形成的标准理论。我们提出了一种新的方法来获得这样远的行星,通过向外迁移的一对行星形成在10 AU区域。两颗在原行星盘的共同间隙中处于平均运动共振的巨行星向外迁移,如果内部的一颗比外部的一颗质量大得多。使用流体动力学模拟,我们表明,它们的半长轴可以增加几乎一个数量级。在一个张开的圆盘中,这对行星应该达到一个渐近半径。这个机制可以解释北落师门b的存在;然后,第二颗更大质量的行星,应该在大约75天文单位处绕着北落师门运行。

英文摘要:

Recent observations of exoplanets by direct imaging, reveal that giant planets orbit at a few dozens to more than a hundred of AU from their central star. The question of the origin of these planets challenges the standard theories of planet formation. We propose a new way of obtaining such far planets, by outward migration of a pair of planets formed in the 10 AU region. Two giant planets in mean motion resonance in a common gap in the protoplanetary disk migrate outwards, if the inner one is significantly more massive than the outer one. Using hydrodynamical simulations, we show that their semi major axes can increase by almost one order of magnitude. In a flared disk, the pair of planets should reach an asymptotic radius. This mechanism could account for the presence of Fomalhaut b ; then, a second, more massive planet, should be orbiting Fomalhaut at about 75 AU.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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