On the origin of wide-orbit ALMA planets: giant protoplanets disrupted by their cores
On the origin of wide-orbit ALMA planets: giant protoplanets disrupted by their cores
复制标题
DOI：
10.1093/mnras/stz2497
复制
发表时间：
2019-11-01
影响因子：
4.8
通讯作者：
Nayakshin, S.
中科院分区：
文献类型：
--
作者：
Humphries, J.;Nayakshin, S.
最近的阿尔马观测可能表明，在只有几百万年历史的原行星盘中，有大量的亚木星行星在非常宽的轨道上运行。这些行星太年轻，距离太远，不可能是通过核心吸积（CA）方案形成的，并且比经典引力不稳定性（GI）理论中产生的气体团质量小得多。最近有人提出，这类行星可能是由GI原行星的部分毁灭形成的：由于巨大核心的生长而产生的能量输出可能会使周围所有或大部分的坍缩前原行星脱离束缚。在这里，我们提出了第一个三维全球光盘模拟，同时解决粮食动态光盘和原行星。我们证实，大质量GI原行星可能会自我毁灭在任意大的距离从主机星星提供固体核心的质量类似于10-20 M-圆点。能够在它们崩溃前的阶段在里面生长。此外，我们发现Masset & VelascoRomero（2017）最近分析的加热力扰动了这些核心远离其气态原行星的中心。这导致了原行星中心非常复杂的尘埃动力学，可能导致在同一原行星内形成多个核心、行星卫星和其他碎片，如星子。对这种行星形成的独特预测是，在0/I类原行星盘的宽轨道上存在亚木星行星。
Recent ALMA observations may indicate a surprising abundance of sub-Jovian planets on very wide orbits in protoplanetary discs that are only a few million years old. These planets are too young and distant to have been formed via the core accretion (CA) scenario, and are much less massive than the gas clumps born in the classical gravitational instability (GI) theory. It was recently suggested that such planets may form by the partial destruction of GI protoplanets: energy output due to the growth of a massive core may unbind all or most of the surrounding pre-collapse protoplanet. Here we present the first 3D global disc simulations that simultaneously resolve grain dynamics in the disc and within the protoplanet. We confirm that massive GI protoplanets may self-destruct at arbitrarily large separations from the host star provided that solid cores of mass similar to 10-20 M-circle dot. are able to grow inside them during their pre-collapse phase. In addition, we find that the heating force recently analysed by Masset & VelascoRomero (2017) perturbs these cores away from the centre of their gaseous protoplanets. This leads to very complicated dust dynamics in the protoplanet centre, potentially resulting in the formation of multiple cores, planetary satellites, and other debris such as planetesimals within the same protoplanet. A unique prediction of this planet formation scenario is the presence of sub-Jovian planets at wide orbits in Class 0/I protoplanetary discs.