Computer Simulation of Hydrogen and Helium in the Interior of Giant Planets

巨行星内部氢和氦的计算机模拟[摘要]将建立一个改进的高温高压下氢氦混合物的状态方程。这将使用新开发的第一性原理技术，采用许多身体模拟（高温下的路径积分蒙特卡罗技术和低温下的密度功能分子动力学）来完成。研究结果将应用于行星天文学中三个突出的问题：1)木星是否有核心？它是否来自核心吸积？2)巨行星内部氢从金属到分子的转变有什么性质，对氦的分布有什么影响？3)是什么机制延长了土星的冷却（观测到的时间是预测的两倍）？此外，这里开发的简并氢氦混合物的状态方程将成为系外巨行星模型的关键组成部分。这些结果有望大大提高我们从凌日和径向速度数据中约束这些行星物理特性的能力。最终的状态方程和在它们之间进行插值的软件将放在网上供公众使用。一名博士后研究员将获得资助，本科生将作为本科生研究经验项目的一部分参与研究。一名博士后研究员将获得资助，本科生将作为本科生研究经验项目的一部分参与研究。

AST-0507321Burkhard MilitzerCarnegie Institution of WashingtonComputer Simulation of Hydrogen and Helium in the Interior of Giant PlanetsABSTRACTAn improved equation of state for hydrogen-helium mixtures at high temperatures and pressures will be developed. This will be accomplished using newly developed first principle techniques employing many body simulations (path integral Monte Carlo techniques at higher temperatures and density functional molecular dynamics at lower temperatures). The results will be applied to three outstanding problems in planetaryastronomy:1) Does Jupiter have a core and did it emerge from core accretion?2) What are the properties of the metallic to molecular transition in hydrogen inside giant planets and how does it affect the distribution of helium?3) What mechanism prolonged Saturn's cooling (observed to be twice as long aspredicted)?Moreover, equations of state for degenerate hydrogen-helium mixtures developed here will be critical components in models of extrasolar giant planets. These results are expected to significantly improve our ability to constrain the physical properties of these planets from transit and radial velocity data.The final equations of state and the software to interpolate among them will be placed on the web for public use.One post-doctoral fellow will be supported and undergraduates will be included in the research as part of a Research Experiences for Undergraduates Site program. One post-doctoral fellow will be supported and undergraduates will be included in the research as part of a Research Experiences for Undergraduates Site program.