【摘要】 在X射线天文学以及辐射物理学中,当硬X射线穿过“冷”的等离子体时所发生的Compton软化是一种重要的辐射转移过程。简要介绍推广的Kompaneets方程,该方程在hv《m_ec~2及kT_e《m_ec~2较宽松的条件下广泛成立,因此不仅能处理Compton硬化过程,而且也适用于Compton软化过程,后者在目前快速发展的X射线和γ射线天文学中十分重要。基于此方程,我们对天体物理中4种常见辐射谱(Gauss型发射谱线、黑体辐射谱、幂律辐射谱和热轫致辐射谱)在Compton软化情况下的港演化进行了数值求解,并同 Monte Carlo模拟结果做比较,证实了推广的 Kompaneets方程的正确性和有效性。最后指出此方程在X射线天文学和γ射线天文学中的重要意义和潜在应用。更多还原

【Abstract】 The down-Comptonization scattering of hard X-ray photons passing through a ’cold’ plasma is an important radiative tranfer process in X-ray astronomy as well as in radiation physics. In this paper, the extended Kompaneets equation is briefly derived under much looser conditions hv << mec2 and kTe << mec2. This equation can be used for both the up-Comptonization (hv << kTe) and the down-Comptonization processes (hv >> kTe). The later is one of the most important processes for the spectral evolution in X-ray and 7-ray astronomy. Based on this equation, some detailed numerical calculations are presented to show the evolution of some typical X-ray spectra in astrophysics in the down-Comptonization, including the emission line with Gaussian profile, the blackbody spectrum, the power-law and the thermal bremsstrahlung spectrum. We compared them with the results of Monte Carlo simulation, and the correctness and effectiveness of the extended Kompaneets equation are confirmed by this way. Finally, we emphasized the potential applications of this equation in X-ray and 7-ray astronomy.更多还原