The physics of the interstellar medium under extreme conditions in Seyfert galaxies

在中心超大质量黑洞周围光学和几何厚度较大的环形气体和尘埃结构的帮助下，所谓的活动星系核统一方案在几何上统一了两类观测到的星系。根据尘埃环面的倾角，中心活动区是可见的(赛弗特1号星系)或不可见(赛弗特2号星系)。尽管用现有最大的望远镜和中红外干涉测量法成功地进行了观测，但这些天体的详细结构和物理特性以及它们的来源仍然鲜为人知：核区域湍流的主要驱动因素是什么，它们是如何构建ISM并为中央黑洞提供燃料的？核活动如何影响周围的ISM？在我们提出的模型中，位于中心几十秒尺度区域的核星团为核中的ISM提供了源，最终形成了几秒尺度的湍流环面。因此，我们的模型将这两个空间区域联系起来，这两个区域都是用自适应光学和干涉测量方法对附近塞弗特星系(常见的)样本进行了很好的研究。由于中心超大质量黑洞的存在所造成的极端条件导致了星系核中的湍流ISM与我们的局域ISM相比具有特殊的动力学和结构特性，我们建议用三维磁流体动力学模拟对其进行详细的研究，并与观测结果进行比较。

With the help of an optically and geometrically thick toroidal gas and dust structure around the central supermassive black hole, the so-called Unified Scheme of Active Galactic Nuclei geometrically unifies two observed classes of galaxies. Depending on the inclination of this dusty torus, the central active region is visible (Seyfert 1 galaxies) or not (Seyfert 2 galaxies). Despite successful observations with the largest available telescopes and interferometry in the mid-infrared, the detailed structure and physics of these objects as well as their origin is still poorly understood: What are the main drivers of turbulence in the nuclear regions and how do they structure the ISM and fuel the central black hole? How does nuclear activity affect the surrounding ISM? In our proposed model, nuclear star clusters in the central tens of parsec scale region provide the source for the ISM in the nucleus, which finally forms the turbulent torus on parsec scale. Thereby, our model links these two spatial regions, which are both well studied with adaptive optics and interferometric methods for a (common) sample of nearby Seyfert galaxies. The extreme conditions due to the presence of the central supermassive black hole lead to peculiar dynamical and structural properties of the turbulent ISM in galactic nuclei in comparison to our local ISM, which we propose to study in detail with three-dimensional magnetohydrodynamical simulations and their comparison with observations.