权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Gas capture by distant protoplanets and the formation of Jovian planets.

遥远的原行星捕获气体和木星行星的形成。

基本信息

批准号：
05833006
负责人：
NAKAZAWA Kiyoshi
金额：
$ 1.41万
依托单位：
Tokyo Institute of Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1993
资助国家：
日本
起止时间：
1993 至 1994
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-05833006/
关键词：
origin of the solar system Kyoto model Jorian planets gas envelope accretion of planetesimals

项目摘要

To clarigy the formation processes of Jovian planets and the origin of their characters, we investigated (i) the static structure of the gas envelope covering a protoplanet and (ii) the collapse process of the unstable gas envelope and developed the simulation code describing (iii) the capture of the nebular gas by a protoplanet.Our main results are summarized as follows.(i) Static structure of the gas envolope covering a protoplanetThe structure of the gas envelope is mainly governed by the energy released in the envelope due to the accretion of planetesimals. Taking into account fragmention of incident planetesimals due to the dynamical pressure, we estimated the energy flux and obtained the static solution of the gas envelope. As a result, we showed that fragmentation of planetesimals fairly reduces the energy flux and the critical core mass and that the critical mass we obtained becomes 1/4 of the value obtained by the previous studies.(ii) The collapse process of the unstable gas envelopeNext, we performed simulations of the collapse of the unstable gas envelope, taking into account the infall of the nebular gas. Futhermore, we analized the dynamical instability of the collapsing gas. Then we showed that the oscillational instability and the mass ejection suggested by Wuchterl (1993) do not occur. Our results support the formation process proposed in Kyoto model.(iii) Capture of the nebular gas by a protoplanetUsing the results in (i) and (ii), we started the development of the new simulation code describing the capture of the nebular gas by a protoplanet. The previous study had a demerit that the way of the gas capture strongly depends on the algorism of the code. We are now developing the new code which can overcome the demerit.

为了阐明类木行星的形成过程及其性质的起源，我们研究了（i）覆盖原行星的气体包层的静态结构和（ii）不稳定气体包层的坍缩过程，并开发了描述（iii）原行星捕获星云气体的模拟程序，主要结果如下：(i)覆盖原行星的气体包层的静态结构气体包层的结构主要受微行星吸积释放的能量控制。考虑到动力压力对入射星子的破碎作用，我们估算了能流，得到了气体包层的静态解。结果表明，微行星的碎裂使能流和临界核质量大大降低，我们得到的临界核质量是以前研究结果的1/4。(ii)不稳定气体包层的坍缩过程接下来，我们对不稳定气体包层的坍缩进行了模拟，考虑了星云气体的坍缩。此外，我们还分析了坍缩气体的动力学不稳定性。然后我们证明了Wuchterl（1993）提出的振荡不稳定性和质量喷射并不发生。我们的结果支持京都模型中提出的形成过程。(iii)利用（i）和（ii）中的结果，我们开始开发描述原行星捕获星云气体的新模拟代码。以前的研究有一个缺点，气体捕获的方式强烈依赖于代码的算法。我们现在正在开发新的代码，可以克服缺点。