论文标题
部分可观测时空混沌系统的无模型预测
An Analytical Fourier-Transformation Model for the Production of Hard and Soft X-Ray Time Lags in AGNs: Application to 1H 0707-495
论文作者
论文摘要
通常使用检测器中的软能带和硬能带之间观察到的时间滞后，从而表征了活性银核的X射线发射的变异性。时间滞后通常是使用复杂的跨频谱计算的，该频谱基于硬和软时序列数据的傅立叶变换。已经注意到，除了更加普遍的硬滞后，一些活跃的银河核显示出软X射线时间滞后。艰难的时期被认为是通过传播波动，空间混响或通过注入热电子云的柔软种子光子的热构造产生的。在过去的十年中，软滞后的物理起源一直是辩论的主题。当前，混响解释被认为是主要理论。在本文中，我们探讨了柔软的X射线时间滞后部分是由单色种子光子的热和散装组合产生的替代可能性，而单色种子光子的热和大量组合，在狭窄的seyfert 1 Galaxy 1H 0707-495中，可能与铁L线发射的荧光相关。在我们的模型中，将种子光子注入积聚流的内部区域中的热，准球电晕。我们基于傅立叶变换的辐射传输方程，开发了一个精确的，依赖时间的分析模型，用于种子光子的热和大量组合，我们证明该模型成功地重现了从1H 0707-495观察到的硬和软时滞后。
The variability of the X-ray emission from active galactic nuclei is often characterized using time lags observed between soft and hard energy bands in the detector. The time lags are usually computed using the complex cross spectrum, which is based on the Fourier transforms of the hard and soft time series data. It has been noted that some active galactic nuclei display soft X-ray time lags, in addition to the more ubiquitous hard lags. Hard time lags are thought to be produced via propagating fluctuations, spatial reverberation, or via the thermal Comptonization of soft seed photons injected into a hot electron cloud. The physical origin of the soft lags has been a subject of debate over the last decade. Currently, the reverberation interpretation is recognized as a leading theory. In this paper, we explore the alternative possibility that the soft X-ray time lags result partially from the thermal and bulk Comptonization of monochromatic seed photons, which in the case of the narrow-line Seyfert 1 galaxy 1H 0707-495, may correlate with fluorescence of iron L-line emission. In our model, the seed photons are injected into a hot, quasi-spherical corona in the inner region of the accretion flow. We develop an exact, time-dependent analytical model for the thermal and bulk Comptonization of the seed photons based on a Fourier-transformed radiation transport equation, and we demonstrate that the model successfully reproduces both the hard and soft time lags observed from 1H 0707-495.
