Magnetohydrodynamics of Protoplanetary Disks

该奖项是根据2009年美国复苏和再投资法案（公法111-5）资助的。这个项目将研究原行星盘的气体动力学，以及圆盘与行星的相互作用。研究工作包括：(1)利用磁旋转不稳定性（MRI）研究原行星盘中的角动量输运，(2)研究由盘-行星相互作用激发的密度波的传播、阻尼和间隙打开，以及(3)可以在大半径范围内研究盘的结构和演化的原行星盘的全全局模型。原行星盘的现实模型是具有挑战性的，因为必须包括各种各样的物理，这些计算将是迄今为止最复杂的。这些模拟将通过整合从现实尺寸分布中提取的数百万粒子的运动，跟踪尘埃颗粒在圆盘中的湍流混合和沉降，与气体动力学自一致。作为12种非平衡电离和重组网络的一部分，要添加的效应是颗粒的复合，所有相关的非理想磁流体动力学（MHD）过程，以及辐射扩散和光学薄冷却，以遵循气体的热力学。所有必要的代码元素已经实现并在雅典娜，一个新的和强大的网格为基础的天体物理MHD代码测试。结果应该是最真实和最准确的原行星盘的非理想MHD模型，以及对行星形成环境和行星与盘的相互作用的深刻理解。该项目包括培训研究生，制作动画和可视化，以便向更广泛的公众传播结果。该团队通过普林斯顿大学的夏季本科生研究项目，积极参与女性和代表性不足的群体参与理论和计算天体物理学。通过开源软件理念，向天体物理学社区提供雅典娜代码，继续促进部门间和国际合作。

AST-0908269StoneThis award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).This project will investigate the gas dynamics of protoplanetary disks, and the interaction of disks with planets. The work includes (1) studies of angular momentum transport by the magnetorotational instability (MRI) in protoplanetary disks, (2) studies of the propagation and damping of, and gap opening by, density waves excited by disk-planet interaction, and (3) fully global models of protoplanetary disks that can investigate the structure and evolution of disks over a wide range of radii. Realistic models of protoplanetary disks are challenging because of the diverse range of physics that must be included, and these calculations will be the most sophisticated yet attempted. These simulations will follow the turbulent mixing and settling of dust grains in the disk self-consistently with the gas dynamics by integrating the motion of millions of particles drawn from a realistic size distribution. Effects to be added are recombination on grains, as part of a twelve-species non-equilibrium ionization and recombination network, all of the relevant non-ideal magnetohydrodynamic (MHD) processes, and radiative diffusion and optically thin cooling to follow the thermodynamics of the gas. All of the necessary code elements have been implemented and tested within Athena, a new and powerful grid-based code for astrophysical MHD. The result should be the most realistic and accurate models of the non-ideal MHD of protoplanetary disks possible, and a deep understanding of the environment of planet formation and the interaction of planets with the disk.The project includes training of graduate students, and animations and visualizations for dissemination of the results to the wider public. The team is vigorously engaged in involving women and under-represented groups in theoretical and computational astrophysics through a Princeton summer undergraduate research program. The work continues to foster interdepartmental and international collaboration by providing access to the Athena code to the astrophysics community through an open-source software philosophy.