弱磁化等温薄吸积盘的轴对称脉动不稳定性  

Axisymmetric Pulsational Instabilities in Weakly Magnetized and Isothermal Accretion Disks

作　　者：汪定雄[1,2] 杨兰田[1,2] 吴少平 

机构地区：[1]华中理工大学物理系 [2]华中师范大学物理系

出　　处：《天体物理学报》1997年第4期364-370,共7页

基　　金：国家自然科学基金;国家攀登计划

摘　　要：本文在不考虑粘滞律的条件下，较详细地讨论了弱磁化等温薄吸积盘的轴对称脉动不稳定性．结果表明，对轴对称扰动，盘内存在４种轴对称振荡模式．仅当Ｂｚ和Ｂφ同时存在时磁场才能影响这些振荡模式的不稳定性．Ｂｚ和Ｂφ对其中２种角频率较高的振荡模式（对应于ωＩ）表现为非稳因素，而对其中２种角频率较低的振荡模式（对应于ωＩ）表现为致稳因素．In this paper, pulsational instabilities of oxisymmetry in weakly magnetized and isothermal accretion disks are investigated in detail without introducing viscosity law.It is shown that four modes of axisymmetric oscillations exist in the disks, arising from the axisymmetric perturbations. Only when both B z and B φ are present does the magnetic field affect the instabilities of these oscillation modes in the disks.B z and B φ act as destabilizing factors for the two oscillation modes with greater angular frequency (ω I ),while act as stabilizing factors for the other two oscillation modes with less angular frequency (ω II ).

关 键 词：吸积盘 脉动不稳定性 磁流体力学 轴对称 弱磁化 

分 类 号：P145.8[天文地球—天体物理]