标题： 激波加速谱中的截断和堆积 显示英文标题

标题： Cut-offs and pile-ups in shock acceleration spectra

摘要： 我们研究了由激波加速产生的粒子谱中由于各种过程引起的截断和堆积，并发现即使在没有能量损失的情况下，低于名义最大能量的加速粒子谱的形状强烈依赖于扩散系数的能量依赖性。 这在许多领域都有影响，例如，在用基于幂律源谱和刚度依赖的银河系扩散逃逸模型拟合观测到的宇宙射线谱时。 在连续能量损失的情况下，可能会出现显著的堆积，这些应在建模由激波加速电子种群产生的同步X射线和逆康普顿伽马射线谱时予以考虑。 我们开发了一种蒙特卡罗/数值技术，用于模拟非连续能量损失情况下的谱形，例如克莱因-尼沙诺区的逆康普顿散射。 我们发现由此产生的截断形状与来自连续过程的截断形状有显著不同，并我们认为这种差异可能通过它们对最近加速电子种群发射的辐射谱的影响而被观测到，例如在年轻的超新星遗迹中可能存在的电子种群。 显示英文摘要

摘要： We have examined cutoffs and pile-ups due to various processes in the spectra of particles produced by shock acceleration, and found that, even in the absence of energy losses, the shape of the spectrum of accelerated particles at energies well below the nominal maximum energy depends strongly on the energy dependence of the diffusion coefficient. This has implications in many areas, for example, in fitting the observed cosmic ray spectrum with models based on power-law source spectra and rigidity dependent diffusive escape from the galaxy. With continuous energy losses, prominent pile-ups may arise, and these should be included when modelling synchrotron X-ray and inverse Compton gamma-ray spectra from a shock-accelerated electron population. We have developed a Monte Carlo/numerical technique to model the shape of the spectrum for the case of non-continuous energy losses such as inverse Compton scattering in the Klein-Nishina regime. We find that the shapes of the resulting cut-offs differ substantially from those arising from continuous processes, and we suggest that such differences could be observable through their effect on the spectrum of radiation emitted by a population of recently accelerated electrons as, for example, may exist in young supernova remnants.