含粘滞和磁场的薄吸积盘不稳定性  

Instabilities of Accretion Disks with Viscosity and Magnetic Field

作　　者：杨兰田[1] 丁世学[1] 吴学兵[1] 谢光中[1] 

机构地区：[1]华中师范大学天体物理研究所,襄阳师范专科学校物理系,中国科学院北京天文台,中国科学院云南天文台

出　　处：《天体物理学报》1994年第4期297-305,共9页

基　　金：国家自然科学基金;国家攀登计划资助

摘　　要：本文采用微扰方法导出色散方程，并在四种情况下详细讨论了薄吸积盘的不稳定性。结果表明：在纯粘滞和纯磁场盘中都存在脉动不稳定性。而且在吸积盘内同时考虑粘滞和磁场时，存在两种不稳定性，一种是脉动不稳定性，另一种是单调不稳定性。同时数值计算还表明，脉动不稳定性更可能存在于盘的内区，而单调不稳定性则只在盘的外区，对短波扰动才有意义。这些结果为解释ＢＬＬａｃ天体、Ｓｅｙｆｅｒｔ星系及类星体等活动星系核的光变现象进一步提供了理论依据。y using the perturbation method,the instabilities of thin accretion disks with viscosity and magnetic field were studied both analytically and numerically.The instability criterions were obtained for four special cases.It has been found that the pulsational instability exists both in pure viscous disks and pure magnetized disks.When viscosity and magnetic field are both considered in a disk,there are two kinds of instabilities.One is pulsational and the other one is monotonic.The former one most probably exists in the inner region of disk while the latter one has physical meaning only to the short wavelength perturbations in the outer disk.Those results are very useful to the explanation of the luminosity variations of BL Lac objects,Seyfert galaxies and quasars.

关 键 词：吸积盘 稳定性 磁场 粘滞 

分 类 号：P157.6[天文地球—天文学]