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Theory of Active Galactic Nuclei

活动星系核理论

基本信息

批准号：
06452024
负责人：
TAKAHARA Fumio
金额：
$ 3.33万
依托单位：
TOKYO METROPOLITAN UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1994
资助国家：
日本
起止时间：
1994 至 1996
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-06452024/
关键词：
Active Galaxies Relativistic Jets Particle Acceleration Gamma-Ray Astronomy X-Ray Astronomy Radiative Transfer Accretion Disks Black Holes 衝撃波相体論的ジェット

项目摘要

1) We have developed the numerical code which self-consistently solves the vertical structure of and emission spectrum from accretion disks. Numerical results are compared with observations of soft X-ray excess and UV bump of active galactic nuclei. We showed that observations are reproduced for nearly Eddington accretion. We also showed that hard X-ray emission is explained by a hot corona.2) We showed that gamma-ray emission from blazars is successfully interpreted in terms inverse Compton scattering. We determined electron spectrum consistent with shock acceleration theory, estmated physical quantities of the jets. We argued that energy density of particles dominates that of magnetic fields and that jet plasma most likely consists of electron-positron pairs. Gamma-ray emission was shown to occur at the distance of 100 to 1000 Schwarzschild radii from the central black hole. These results give an important clue to the bulk acceleration mechanism of jets.3) We studied diffusive particle acceleration by shock waves, especially oblique shocks by the Monte Carlo method. We have shown that acceleration time scale is significantly shortened compared with parallel shocks.4) We studied atomic and plasma processes which are important in diagnosing the physical states of hot gas in active galactic nuclei. We have applied them to various astrophysical objects.

1)我们开发了自洽求解吸积盘垂直结构和发射谱的数值程序。数值计算结果与活动星系核的软X射线过剩和紫外隆起的观测结果进行了比较。我们表明，观察再现近爱丁顿吸积。我们还表明，硬X射线发射是由一个热的日冕。2）我们表明，从耀变体的γ射线发射是成功地解释了逆康普顿散射。测定了符合冲击加速理论的电子能谱，估算了射流的物理量。我们认为，粒子的能量密度占主导地位的磁场和射流等离子体最有可能由电子-正电子对。伽马射线的发射被证明发生在距离中心黑洞100到1000史瓦西半径的地方。这些结果为研究喷流的整体加速机制提供了重要线索。3）用Monte Carlo方法研究了激波尤其是斜激波对扩散粒子的加速。我们已经表明，加速的时间尺度相比，平行冲击显着缩短。4）我们研究了原子和等离子体过程，这是重要的诊断在活动星系核的热气体的物理状态。我们已将它们应用于各种天体物理物体。