THEORETICAL STUDIES ON HIGH ENERGY ASTROPHYSICS

在这个项目的三年任期内，每个成员都进行了个别课题的研究，并发表了许多论文。每年举行一次研究会议，以增进对共同概念和物理过程以及各种高能天体之间的相互关系的相互了解。主要研究成果如下：1.磁场在电磁场中的作用。通过大规模的数值模拟对吸积盘进行了研究。阐明了它们撞击黑洞的行为以及对X射线发射时间变化的影响。还提出了制作磁铁塔的可能性。通过辐射流体力学的蒙特卡罗模拟，对相对论喷流形成的Wien火球模型进行了定量研究。利用多频观测数据对急流的物理状态进行了分析。SNR SN1006和RXJ1713.7的粒子加速区域的空间尺寸非常小，并得到了对扩散加速的强烈约束。通过数值模拟，阐明了电子在无碰撞激波作用下利用微观电场结构的冲浪机制加速电子的过程。

During the three year term of this project, each member has done research on individual subjects and published many papers. For each year a research meeting was held to boost mutual understanding of common concepts and physical processes, and interrelations among various high-energy astrophysical objects. Major achievements are as follows :1. The role of magnetic fields in. accretion disks has been investigated through large scale numerical simulations. Their behavior in impinging into the black hole and effect on time variations in X-ray emission was clarified. A possibility of making a magnetic tower was also suggested.2. The Wien fireball model for the formation of relativistic jets was quantitatively investigated through the Monte Carlo simulation of radiation hydrodynamics. Analysis of the physical state of jets was also made based on multi-frequency observational data.3. The spatial size of the region where particle acceleration is occurring in SNR SN1006 and RXJ1713.7 was found to be extremely small and strong constraints on diffusive acceleration were obtained. Electron acceleration process through surfing mechanism utilizing microscopic electric field structure associated with collisionless shocks was clarified through numerical simulation.