Understanding Cataclysmic Variable Accretion Disk Dynamics and Viscosity

AST 0205902PI伍德一组相互作用的星星系统称为灾难性的变量作为一个了不起的实验室，研究天体物理吸积过程如何工作。在这组双星中有许多大类的物体，每一类又分为不同爆发和静止行为的物体。为了理解这些系统中潜在的吸积物理学，已经花费了大量的观测努力。现在，通过更好的算法和桌面超级计算以及三维流体动力学代码，可以解决曾经看似棘手的计算问题，并且已经取得了进展。该项目将推动对一个特定的，长期以来令人困惑的，在SU大熊座型系统中观察到的现象：在特别明亮的爆发期间观察到所谓的超级驼峰。PI已经成功地模拟了近似的超级驼峰行为，使用他的光滑粒子流体动力学代码在一个完整的三维模式。 光变曲线中的超级峰是倾斜吸积盘的真正不稳定性。该项目将通过增加磁场引起的盘粘性来扩展工作，并创建光变曲线网格和模型盘，这些网格和模型盘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.***