标题： 活动星系核中心100秒差距的各向同性中红外辐射 显示英文标题

标题： Isotropic Mid-Infrared Emission from the Central 100 pc of Active Galaxies

摘要： 尘埃重新处理活动星系核 (AGN) 的固有辐射，在更长的波长上显现出来。 观测到的中红外 (MIR) 光度从根本上依赖于中心引擎的光度，但详细来说，它还依赖于周围尘埃的几何分布。 为了量化这种关系，我们在中红外波段观测了附近的正常 AGN，以达到优于 100 秒差距的空间分辨率，并使用吸收修正后的 X 射线光度作为固有 AGN 发射的代理。 我们发现光学分类的 Seyfert 1 和 2 星系之间没有显著差异。 在光学和红外波长上的光谱差异表明，AGN 的直接环境并非球对称，这与标准统一的 AGN 模型不同。 对块状圆环辐射传递模型的定量分析显示，块状局部环境可以解释这种对观测几何的依赖性，同时产生近似各向同性的中红外连续发射，尽管在这些波长下物质并非光学薄。 我们在最小尺度测量中发现了 X 射线 / 中红外相关性的一些光度依赖性，这可能表明与恒星形成相关的增强尘埃发射，即使是在小于 100 秒差距的尺度上也是如此。 显示英文摘要

摘要： Dust reprocesses the intrinsic radiation of active galactic nuclei (AGNs) to emerge at longer wavelengths. The observed mid-infrared (MIR) luminosity depends fundamentally on the luminosity of the central engine, but in detail it also depends on the geometric distribution of the surrounding dust. To quantify this relationship, we observe nearby normal AGNs in the MIR to achieve spatial resolution better than 100 pc, and we use absorption-corrected X-ray luminosity as a proxy for the intrinsic AGN emission. We find no significant difference between optically classified Seyfert 1 and 2 galaxies. Spectroscopic differences, both at optical and IR wavelengths, indicate that the immediate surroundings of AGNs is not spherically symmetric, as in standard unified AGN models. A quantitative analysis of clumpy torus radiative transfer models shows that a clumpy local environment can account for this dependence on viewing geometry while producing MIR continuum emission that remains nearly isotropic, as we observe, although the material is not optically thin at these wavelengths. We find some luminosity dependence on the X-ray/MIR correlation in the smallest scale measurements, which may indicate enhanced dust emission associated with star formation, even on these sub-100 pc scales.