标题： 一种自洽的非平衡态冲击加热等离子体模型，用于从X射线观测中直接约束参数 显示英文标题

标题： A self-consistent model of shock-heated plasma in non-equilibrium states for direct parameter constraints from X-ray observations

摘要： 对超新星遗迹等受到冲击波加热的等离子体的X射线观测通常表现出温度和电离非平衡的特征。为了准确解释这些观测结果，对平衡过程进行精确计算至关重要。在这里，我们提出了一种自洽模型，用于描述冲击波加热等离子体的热X射线发射，该模型考虑了温度和电离非平衡条件。对于给定的激波速度和初始电子与离子温度比值，通过同时求解温度和电离的弛豫过程，计算了每种元素的温度和电离状态的时间演化。由此得到的热X射线谱通过结合我们的模型与AtomDB光谱代码来合成。我们将我们的模型与XSPEC软件包中的恒温非平衡电离模型\texttt{内}进行比较，发现\texttt{内}模型低估了电离时间尺度约30%。我们在XSPEC中实现了我们的模型，以直接约束激波波前的性质，例如激波速度和碰撞电子加热效率，从冲击后等离子体的热X射线发射中得出。我们将此模型应用于N132D超新星遗迹的存档钱德拉数据，得出了激波速度为$\sim 800~\mathrm{km\,s^{-1}}$的限制，这与先前的光学研究一致。 显示英文摘要

摘要： X-ray observations of shock-heated plasmas, such as those found in supernova remnants, often exhibit features of temperature and ionization non-equilibrium. For accurate interpretation of these observations, proper calculations of the equilibration processes are essential. Here, we present a self-consistent model of thermal X-ray emission from shock-heated plasmas that accounts for both temperature and ionization non-equilibrium conditions. For a given pair of shock velocity and initial electron-to-ion temperature ratio, the temporal evolution of the temperature and ionization state of each element was calculated by simultaneously solving the relaxation processes of temperature and ionization. The resulting thermal X-ray spectrum was synthesized by combining our model with the AtomDB spectral code. Comparison between our model and the \texttt{nei} model, a constant-temperature non-equilibrium ionization model available in the XSPEC software package, reveals a 30\% underestimation of the ionization timescale in the \texttt{nei} model. We implemented our model in XSPEC to directly constrain the shock wave properties, such as the shock velocity and collisionless electron heating efficiency, from the thermal X-ray emission from postshock plasmas. We applied this model to archival Chandra data of the supernova remnant N132D, providing a constraint on the shock velocity of $\sim 800~\mathrm{km\,s^{-1}}$, in agreement with previous optical studies.