Abstract Due to the compactness active galactic nuclei (AGN) are still unresolved with optical observations. However, structure and physical conditions of the matter in their central parts are especially important to study the processes of the matter accretion to supermassive black holes and eventually these investigations are essential to understand the galaxy evolution. Polarization contains information about the interaction of electromagnetic waves with the environment and provides information about the physical processes in the central regions of the AGNs that could not be found with the help of other optical observations. In this paper the importance of applying polarimetry methods to the study of geometry, kinematics, and physical processes in AGN in polarized light is discussed. An overview of the mechanisms of polarization formation, their connection with different structures and scales are provided. Also, we overview the polarimetric investigations based on different assumptions that are done using the observations conducted in Special Astrophysical Observatory of Russian Academy of Sciences.

中文翻译：

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偏振光下的活动星系核

摘要 由于活动星系核 (AGN) 的致密性，光学观测仍未解决。然而，中心部分物质的结构和物理条件对于研究物质吸积到超大质量黑洞的过程尤为重要，最终这些研究对于理解星系演化至关重要。极化包含有关电磁波与环境相互作用的信息，并提供有关 AGN 中心区域物理过程的信息，而这些信息在其他光学观测的帮助下无法找到。在本文中，讨论了将偏振测量方法应用于研究偏振光中 AGN 中的几何、运动学和物理过程的重要性。极化形成机制的概述，提供了它们与不同结构和尺度的联系。此外，我们概述了基于不同假设的极化研究，这些假设是使用俄罗斯科学院特殊天体物理天文台进行的观测完成的。