含粘滞的弱磁化吸积盘的非轴对称脉动不稳定性  

THE NONAXISYMMETRIC PULSATIONAL INSTABILITY IN WEAKLY MAGNETIZED ACCRETION DISKS WITH VISCOSITY

作　　者：汪定雄[1] 杨兰田[2] 

机构地区：[1]华中理工大学物理系,武汉430074 [2]华中师范大学天体物理所,武汉430070

出　　处：《天文学报》1997年第3期250-256,共7页Acta Astronomica Sinica

基　　金：国家自然科学基金;国家攀登计划资助项目

摘　　要：本文讨论了一种含扩散型粘滞的弱磁化等温吸积盘模型．在作者原有工作的基础上研究了吸积盘对非轴对称扰动（含径向、环向和垂向三个方向的扰动）所表现的脉动不稳定性．结果表明，径向扰动是最重要、最根本的扰动：在无径向扰动时，吸积盘中不存在环向扰动与垂向扰动所产生的脉动不稳定性．在径向扰动存在时，吸积盘除了可能存在纯径向脉动不稳定性外，还可能存在由于径向扰动与垂向扰动的耦合所引起的轴对称脉动不稳定性，以及由于径向扰动与环向扰动的耦合所引起的非轴对称脉动不稳定性．当上述三个方向的扰动并存时，对应的非轴对称脉动不稳定性也可能存在．A model of weakly magnetized, isothermal accretion disk with the diffusion-type viscosity is investigated in this paper. The pulsational instability of the disks, arising from nonaxisymmetric perturbations (including radial, azimuthal and vertical perturbations) is discussed on the ground of the authors previous work. It is shown that the radial perturbation is the most important and essential one. There are no pulsational instabilities arising from either azimuthal or vertical perturbations in the absence of the radial perturbation. In contrast, in the presence of the radial perturbation, there exist not only the pure radial pulsational instability, but also those which arise from the coupled radial-vertical perturbation and the coupled radial- azimuthal ones. In the case that the above perturbations in the three directions coexist, the corresponding nonaxisymmetric pulsational instability will probably exist.

关 键 词：吸积盘 磁流体动力学 不稳定性 脉动 含粘滞 

分 类 号：P145.8[天文地球—天体物理]