The composition of Jupiter: sign of a (relatively) late formation in a chemically evolved protosolar disc
The composition of Jupiter: sign of a (relatively) late formation in a chemically evolved protosolar disc
复制标题
木星的组成：化学演化的原太阳盘（相对）较晚形成的迹象
DOI：
10.1111/j.1745-3933.2006.00137.x
复制
发表时间：
2006
影响因子：
--
通讯作者：
R. Hueso
中科院分区：
文献类型：
--
作者：
T. Guillot;R. Hueso
有人提出，伽利略在木星大气层中发现的稀有气体的富集可以用它们在冷的微行星中的传递来解释。相反，我们认为这是一个迹象，表明行星形成于化学演化的圆盘中，并且在行星的包络捕获阶段，惰性气体主要以气态形式获得。
我们表明，在寒冷的外层，这些颗粒在温度低于20-30 K的惰性气体的冷凝，并从高磁盘高度蒸发的组合沉降到磁盘中平面的颗粒，有效地导致一个渐进的，适度的富集盘。惰性气体从热的内盘区域（例如木星形成区域）的颗粒中蒸发的事实并不令人担忧，因为负温度梯度阻止对流将物质带入蒸发区域。我们表明，Ar，Kr和Ar在木星的102倍的太阳富集，因此自然地解释了一个连续的增长的行星所支配的粘性扩散在原太阳盘与蒸发盘和其渐进的富集在百万年的时间尺度。
It has been proposed that the enrichment in noble gases found by Galileo in the atmosphere of Jupiter can be explained by their delivery inside cold planetesimals. We propose instead that this is a sign that the planet formed in a chemically evolved disc and that noble gases were acquired mostly in gaseous form during the envelope capture phase of the planet.
We show that the combined settling of grains to the disc mid-plane in the cold outer layers, the condensation of noble gases on to these grains at temperatures below 20–30 K, and the evaporation from high disc altitudes effectively lead to a progressive, moderate enrichment of the disc. The fact that noble gases are vaporized from the grains in the hot inner disc regions (e.g. Jupiter formation region) is not a concern because a negative temperature gradient prevents convection from carrying the species into the evaporating region. We show that the ∼2 times solar enrichment of Ar, Kr and Xe in Jupiter is hence naturally explained by a continuous growth of the planet governed by viscous diffusion in the protosolar disc in conjunction with an evaporation of the disc and its progressive enrichment on a million-year time-scale.