THEORETICAL STUDY OF COSMIC RAY ASTROPHYSICS

1.研究了宇宙线加速的位置和机制。在磁场方向与激波法线不平行的情况下，解析地估计了斜激波可获得的最大能量。对于超新星遗迹和射电星系，分别为10^lt；16和10^lt；20&gt；EV，这可能解决了这个长期存在的问题。此外，我还进行了蒙特卡罗模拟，证实了解析估计。几何效应对加速过程的影响正在研究中。我研究了一种从观测上证实加速度理论的可能性。由于加速地点的宇宙射线谱预计会比在地球上观察到的要平坦得多，所以在加速地点发射的伽马射线谱也应该是平坦的。我计算了超新星遗迹的预期伽马射线通量，发现该通量略低于现有仪器的探测极限，可以用切伦科夫望远镜和在建的EAS阵列观测到。我还研究了白鹭最近在CGRO卫星上发现的来自blazar的GeV伽马射线发射。我认为伽马射线是由束喷流中的相对论电子对软光子的逆康普顿散射产生的。我将冲击波加速理论应用于这个问题；我发现，由于辐射冷却，电子光谱应该出现断裂，并且这种断裂对应于3C279大约10 MeV的光子能量。

1. The site and mechanism of cosmic ray acceleration are studied. The attainable maximum energy for oblique shocks, where the magnetic field direction and the shock normal is not parallel, is estimated analytically. It turns out to be 10^<16> and 10^<20>eV for supernova remnants and radio galaxies, respectively, which possibly resoved the long standing problem. Further, I have made Monte Carlo simulations, which confirmed the analytic estimates. Geometrical effects on the acceleration process is under investigation.2. I studied a possibility to observationally confirm the acceleration theory. Since the cosmic ray spectrum at the acceleration site is expected to be much flatter than that observed on the earth, the gamma-ray spectrum emitted at the acceleration site should also be flat. I calculated expected gamma-ray flux from supernova remnants, and found that the flux is just below the detection limit of existing instruments and can be observable by Cerenkov telescopes and EAS arrays under construction.3. I also studied GeV gamma-ray emission from blazars which have recently been discovered by EGRET on board CGRO satellite. I argued that gamma-rays are produced by the inverse Compton scattering off soft photons by relativistic electrons in a beamed jet. I applied shock acceleration theory to this problem ; I found that a break in the electron spectrum should appear due to radiative cooling and that this break corresponds to the photon energy of around 10MeV for 3C279.