黑洞X射线双星中的高能粒子加速及偏振辐射特性

A black hole X-ray binary is a product of the evolution in the late of the high-mass stellar binary system, which is one of celestial systems with high-energy activities at the stellar level. This class system, which consists of a central black hole, an accretion disk around the black hole, jets and a companion star, has become an important frontier in the current research on astrophysics. By establishing the theoretical model, using analytical methods and especially numerical simulations, and combing with observational data, we plan to study their high-energy physical processes. The research content includes the acceleration theory of energetic particles, its application to black hole X-ray binaries and polarization analysis methods, that is, the process of energy dissipation of both the stochastic particle acceleration and diffusion shock wave, the influence of both radiation fields and magnetohydrodynamic (MHD) turbulence on magnetic reconnection processes, studies of the characteristics of multi-frequency polarization radiation, and an application of the polarization analysis technology of synchrotron fluctuations. Based on the fundamental physical theories of first principles, we are committed to establish a self-consistent polarized radiation jet model in order to explain important observations, determine what dominant acceleration mechanism of particles is, and constrain the origin of non-thermal high-energy particles and multiband radiation. Furthermore, through the applications of the polarization frequency analysis and polarization spatial analysis technologies, we also try to understand the fundamental properties of the MHD turbulence presented in black hole X-ray binaries. The implementation of this project will help us to reveal various physical processes around a stellar-mass black hole，and will provide a certain enlightenment function for using relevant knowledge to study other astrophysical problems, such as high-energy cosmic rays and AGNs.

黑洞X射线双星是由中央黑洞、环绕黑洞的吸积盘、喷流及伴星等构成的双星系统，是恒星层次上呈现高能活动现象的天体系统之一，是当今天体物理学研究的一个重要前沿领域。本项目计划通过理论模型构建，解析尤其是数值模拟结合相关观测数据，研究这类天体系统中发生的高能物理过程。内容包括随机粒子及扩散激波加速、辐射磁重联及湍流磁重联加速过程、多频偏振辐射特性的研究、同步波动偏振分析技术的应用。本项目计划: ① 建立自洽的偏振辐射模型，致力于多波段辐射起源及起主导作用的粒子加速机制的确定；② 研究磁流体力学湍流及辐射场对该类天体中发生的磁重联过程的影响；③ 通过偏振频率分析及偏振空间分析技术的应用，揭示磁流体力学湍流的基本性质。本项目的实施将有助于揭示恒星级黑洞周围发生的各种高能物理过程，并对我们运用这些知识研究其他相关天体物理问题如高能宇宙线、活动星系核等有重要帮助。

X射线双星是具有高能活动现象的天体物理系统之一，是现代天体物理学研究的一个重要前沿领域。该类天体的辐射波段涉及范围较广，从射电波段到高能伽玛射线波段，因此研究粒子的加速和湍流磁场的性质可以更好地理解其多波段辐射过程。.本项目针对湍流磁场对X射线双星高能活动的重要性，开展了X射线双星中粒子加速机制和MHD湍流性质的相关研究工作。项目组利用模拟湍流磁场的数据立方体，主要通过同步辐射涨落理论研究磁流体动力学湍流的基本性质以及测量磁场的方向。项目实施主要取得了以下研究成果：（1）通过模拟真实的天体物理环境，成功地恢复了磁流体动力学湍流的功率谱；（2）利用四极比模的统计方法，从观测的角度研究了磁流体湍流以及其三种基本模的各向异性，得到的结果与早期研究得到的结论一致；（3）利用同步辐射梯度技术，可以很好地测量低频强法拉第旋转情况下的磁场方向，这相对于传统的同步偏振辐射强度技术是一个很大的突破；（4）利用同步辐射的高级诊断量的梯度技术也可以很好的恢复湍流磁场的方向，且在低频强法拉第旋转情况下也是适用的；（5）测量湍流磁场的几种统计技术的协同作用，可以提高磁场方向测量的稳健性；（6）发现湍流磁场有有效促进X射线喷流中粒子的加速和主导被加速粒子能谱的分布特征。.