Computational Modeling of Interiors of Sub-Neptunes and Gas Giant Planets

PI和他的团队将进行理论上的努力，以提高对我们太阳系和其他太阳系外行星系统中冰和气体巨行星的内部，形成和演化的理解。他们将应用计算机模拟技术来研究暴露在极端温度和压力下的行星内部物质，这些物质在实验室中是无法复制的。他们将通过模拟气体的热力学性质来做到这一点，比如状态方程（EOS），它给出了温度、压力和材料密度之间的数学关系。研究人员将把他们的模型应用于一组质量小于海王星的冰巨行星。他们还计划为天王星和海王星的内部建立一个包括钻石层的新模型，以解释这些行星的特殊磁场。他们将与合作者一起准备互补的高压实验，并更新木星和土星的模型。计算结果将提供给天文学界用于行星和恒星内部模型。他们还将在计算研究技术方面培训研究生和本科生。为了实现这一目标，研究人员将把该小组新的从头算氢氦EOS纳入现有的代码中，以模拟旋转的巨行星。他们还将更新液态水和超离子水的相图，并模拟这些行星上水、甲烷和氨的混合物。他们将利用这些结果来改进木星和土星的演化模型，以及天王星和海王星的磁场模型。他们还将把EOS表合并到恒星演化代码MESA中，并向社区提供关于固体、液体、超离子和低密度分子系统的从头算吉布斯自由能计算结果。

The PI and his team will carry out a theoretical effort to improve understanding of the interior, formation and evolution of ice- and gas-giant planets in our solar system and other extrasolar planetary systems. They will apply computer simulations techniques to study planetary interior materials exposed to extreme temperatures and pressures that cannot be reproduced in the laboratory. They will do this by simulating thermodynamic properties of the gases, such as the equation of state (EOS), which gives the mathematical relationship between temperature, pressure and density of a material. The investigators will apply their models to a collection of ice giant planets with masses less than that of Neptune. They also plan to develop a new model for Uranus' and Neptune's interior that includes a diamond layer, in order to explain these planets' peculiar magnetic fields. They will work with collaborators to prepare complementary high-pressure experiments, and to update models of Jupiter and Saturn. Computational results will be provided to the astronomical community for use in planetary and stellar interior models. They will also train graduate and undergraduate students in computational research techniques.The investigators will accomplish this by incorporating the group's new ab initio Hydrogen-Helium EOS into existing code in order to model rotating giant planets. They will also update phase diagrams for liquid and superionic water and simulate the mixtures of water, methane and ammonia in these planets. They will use these results to improve evolutionary models of Jupiter and Saturn, and magnetic field models of Uranus and Neptune. They will also incorporate the EOS tables into the stellar evolution code MESA, and provide results to the community about ab initio Gibbs free energy calculations in solid, liquid, superionic and lower-density molecular systems.