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

借助中央超大质量黑洞周围的光学和几何厚度的环形气体和尘埃结构，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。根据这个尘埃环的倾角，中心活动区域是可见的（塞弗特1星系）或不可见的（塞弗特2星系）。尽管使用最大的可用望远镜和中红外干涉测量仪进行了成功的观测，但这些天体的详细结构和物理特性以及它们的起源仍然知之甚少：核区域湍流的主要驱动因素是什么？它们如何构建ISM并为中心黑洞提供燃料？核活动如何影响周围的ISM？在我们提出的模型中，中心几十秒差距尺度区域的核星团为核内的ISM提供了源，最终形成了秒差距尺度的湍流环面。因此，我们的模型将这两个空间区域联系起来，这两个空间区域都通过自适应光学和干涉测量方法对附近塞弗特星系的一个（常见）样本进行了很好的研究。由于中心超大质量黑洞存在的极端条件导致星系核湍流ISM与我们的局部ISM相比具有特殊的动力学和结构特性，我们建议通过三维磁流体动力学模拟及其与观测结果的比较来详细研究。

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.