论文标题
高密度气体的光电离
Photoionization Models for High Density Gas
论文作者
论文摘要
从许多吸积驱动的物体（包括X射线二进制物和主动银河核（AGN））中观察到相对宽缩和红移6.4-6.9 keV铁K线。靠近中央发动机的气体的存在意味着如果气体要部分离子化，则大量的辐射强度和相应的气体密度相应。简单的估计表明，需要高气密度以允许铁对电离的生存。这些足够高，以至于许多原子过程的速率受到与附近离子和电子相互作用相关的机制的影响。辐射强度足够高，以至于刺激过程很重要。当前用于解释相对论线的大多数模型都使用旨在在低密度和忽视刺激过程中使用的原子速率系数。到目前为止，我们已经提出了原子结构的计算，其目的是在与紧凑型物体附近发射气体一致的密度上提供物理适当的模型。在本文中，我们将这些速率应用于光电离计算，并产生电离平衡曲线和X射线发射和不粘液，这适用于高密度和高辐射强度。我们程序的最后一步将在随后的论文中介绍：模型大气计算，将这些速率纳入合成光谱。
Relativistically broadened and redshifted 6.4 -- 6.9 keV iron K lines are observed from many accretion powered objects, including X-ray binaries and active galactic nuclei (AGN). Existence of gas close to the central engine implies large radiation intensities and correspondingly large gas densities if the gas is to remain partially ionized. Simple estimates indicate that high gas densities are needed to allow survival of iron against ionization. These are high enough that rates for many atomic processes are affected by mechanisms related to interactions with nearby ions and electrons. Radiation intensities are high enough that stimulated processes can be important. Most models currently in use for interpreting relativistic lines use atomic rate coefficients designed for use at low densities and neglect stimulated processes. In our work so far we have presented atomic structure calculations with the goal of providing physically appropriate models at densities consistent with line-emitting gas near compact objects. In this paper we apply these rates to photoionization calculations, and produce ionization balance curves and X-ray emissivities and opacities which are appropriate for high densities and high radiation intensities. The final step in our program will be presented in a subsequent paper: Model atmosphere calculations which incorporate these rates into synthetic spectra.
