Understanding Cataclysmic Variable Accretion Disk Dynamics and Viscosity

一组相互作用的双星系统被称为巨变星，它是一个奇妙的实验室，用来研究天体物理吸积过程是如何工作的。在这组双星中有许多大类的天体，每一类又进一步分为具有不同爆发和静止行为的天体。在试图理解这些系统中潜在的吸积物理方面，已经花费了大量的观测努力。现在，曾经看似棘手的计算问题可以通过更好的算法和带有三维流体动力学代码的桌面超级计算来解决，并且已经取得了进展。这个项目将推动对在SU大熊座型系统中观察到的一个特殊的、长期令人困惑的现象的建模工作：在特别明亮的爆发期间观察到的所谓的超级驼峰。PI已经成功地用他的光滑粒子流体力学代码在全三维模式下模拟了近似的超驼峰行为。光曲线中的超峰是倾斜吸积盘真正的不稳定性。这个项目将通过增加由于磁场导致的磁盘粘度来扩展工作，并创建光曲线网格和建模磁盘，这些网格将作为地图集交付给天文学界

AST 0205902PI WoodThe set of interacting binary star systems called cataclysmic variables serves as a marvelous laboratory to study how astrophysical accretion processes work. In that group of binaries are a number of broad categories of objects, each category further divided into classes of objects of different outburst and quiescence behaviors. Significant amounts of observational effort has been expended in an attempt to understand the underlying accretion physics in these systems Now once seemingly intractable computational problems are accessible via better algorithms and desktop supercomputing with 3-dimensional hydrodynamic codes, and progress has been made.This project will advance efforts to model a particular, and for a long-while puzzling, phenomenon observed in SU Ursa Majoris-type systems: so-called superhumps observed during especially bright outbursts. The PI has successfully modeled approximate superhump behavior using his smoothed particle hydrodynamic code in a fully 3-dimensional mode. The superhumps in light curves are true instabilities of tilted accretion disks. This project will expand the work by adding disk viscosity due to magnetic fields and creating a grid of light curves and modeled disks that will be delivered to the astronomy community as an atlas.***