活动星系核尘埃环的理论和唯象模型
Theoretical and phenomenological models of AGN torus
The dusty torus model of active galactic nuclei (AGN) is a crucial aspect of our understanding of the central engine of these objects. The theoretical model for the AGN torus was originally explained by a disk wind dominated by MHD and/or radiation pressure. Subsequently, a "failed wind" scenario has been developed to explain the observation of the BLR. And the radiatively inefficient accretion flow (RIAF) also has been proposed to explain the low-luminosity scenario of LLAGNs. The phenomenological model has evolved over time from simple uniform dust distributions to more complex, clumpy geometries. The clumpy formalism is now commonly used in torus models to prevent dust destruction. Additionally, several hydrodynamical simulations predict that the torus is a multiphase structure, containing a combination of smooth and clumpy dust distributions. Recent observations using IR interferometry have shown evidence for a polar dust component, leading to the development of clumpy disc+wind models. In this talk, we will briefly introduce the theoretical model and then describe the dust geometries and compositions, sublimation temperatures, and main parameters of different phenomenological models, and finally compare the various phenomenological models to assess how well they fit the observed data.
