活动星系核的有磁薄吸积盘结构及其冕区辐射

ON THE STRUCTURE OF MAGNETIZED THIN ACCRETION DISKS OF ACTIVE GALACTIC NUCLEI AND THEIR CORONAL RADIATIONS

本文以磁应力取代粘滞传递角动量,考察了冻结磁场对轴对称稳态薄吸积盘内区结构的影响.结果表明:吸积盘为类开普勒盘,其总光度为标准α模型的两倍.在盘内边界附近存在一个狭窄的冷却区,由于环向磁场的作用,高度准直的喷流很可能在此形成.本文还分析了吸积盘冕区形成的可能性,并探讨了冕区产生的宽波段辐射,其结果能较为全面地解释活动星系核的高光度、光变以及"紫外超"等现象.

By using magnetic stress in place of viscosity as the mechanism for angular momentum transfer, the influence of frozen magnetic field on the structure of a geometrically thin accretion disk is examined in this paper. It is shown that the magnetized disk is quasi-Keplerian and its total luminosity is twice of that in the standard disk model. In the inner region, there exists a narrow cool region and the highly collimated jet is formed under the action of the azimuthal component of magnetic field. Also in this paper, such a possibility is discussed that a magnetized corona may be formed near the surface of accretion disk and the wide band radiation from the corona is studied. By using the magnetized disk-corona model we suggested here, one can easily and reasonably explain the major AGN's properties such as the radiation, variation, the opticalultraviolet-soft x-ray 'big bump', etc.