Redefining the Torus: A Unifying View of AGNs in the Infrared and Submillimeter
Redefining the Torus: A Unifying View of AGNs in the Infrared and Submillimeter
复制标题
DOI：
10.3847/1538-4357/ab4591
复制
发表时间：
2019-09
期刊：
影响因子：
--
通讯作者：
S. Hönig
中科院分区：
文献类型：
--
作者：
S. Hönig
高角分辨率红外光谱和亚毫米干涉测量技术的出现，使得对活动星系核(AGN)的空间分辨率观测成为可能，这些活动星系核通常被称为“环面”。虽然分子谱线显示了大质量圆盘的存在，但红外观测似乎被一种被解释为尘埃风的强极性成分所主导。本文旨在利用活动星系核在每个波段的共同特征和一套简单的物理原理来形成对这些看似矛盾的观测的统一看法：尘埃分子气体通过具有小到中等尺度高度的圆盘从∼100PC的星系尺度进入亚帕尔秒环境。由于红外线辐射压力，圆盘内部的热膨胀，并从黑洞的引力势中释放出大量流入的气体，为发射由活动星系核的辐射压力驱动的风提供了条件。尘埃风以∼0.1-100M⊙yr−1的数量级将质量反馈到星系中，这取决于活动星系核的光度和爱丁顿比。AGN统一所要求的角度相关遮挡是由圆盘、风和风发射区的组合提供的。
The advent of high-angular-resolution IR and submillimeter interferometry allows for spatially resolved observations of the parsec-scale environment of active galactic nuclei (AGNs), commonly referred to as the “torus.” While molecular lines show the presence of large, massive disks, the IR observations appear to be dominated by a strong polar component that has been interpreted as a dusty wind. This paper aims at using characteristics shared by AGNs in each of the wavebands and a set of simple physical principles to form a unifying view of these seemingly contradictory observations: dusty molecular gas flows in from galactic scales of ∼100 pc to the subparsec environment via a disk with small to moderate scale height. The hot, inner part of the disk puffs up due to IR radiation pressure and unbinds a large amount of the inflowing gas from the black hole’s gravitational potential, providing the conditions to launch a wind driven by the radiation pressure from the AGN. The dusty wind feeds back mass into the galaxy at a rate of the order of ∼0.1–100 M⊙ yr−1, depending on the AGN luminosity and Eddington ratio. Angle-dependent obscuration as required by AGN unification is provided by a combination of disk, wind, and wind-launching region.