X-ray absorption and 9.7 um silicate feature as a probe of AGN torus structure
Jun Xu, Mouyuan Sun, Yongquan Xue, Junyao Li, Zhicheng He
备注：
17 pages, 12 figures, Accepted to Research in Astronomy and Astrophysics (a new version with appropriate top margins so that the few bottom lines appear properly)
The dusty torus plays a vital role in unifying active galactic nuclei (AGNs). However, the physical structure of the torus remains largely unclear. Here we present a systematical investigation of the torus mid-infrared (MIR) spectroscopic feature, i.e., the 9.7 um silicate line, of $175$ AGNs selected from the Swift/BAT Spectroscopic Survey (BASS). Our sample is constructed to ensure that each of the $175$ AGNs has Spizter/IRS MIR, optical, and X-ray spectroscopic coverage. Therefore, we can simultaneously measure the silicate strength, optical emission lines, and X-ray properties (e.g., the column density and the intrinsic X-ray luminosity). We show that, consistent with previous works, the silicate strength is weakly correlated with the hydrogen column density ($N_\mathrm{H}^\mathrm{X}$), albeit with large scatters. For X-ray unobscured AGNs, the silicate-strength-derived $V$-band extinction and the broad-H$α$-inferred one are both small; however, for X-ray obscured AGNs, the former is much larger than the latter. In addition, we find that the optical type 1 AGNs with strong X-ray absorption on average show significant silicate absorption, indicating that their X-ray absorption might not be caused by dust-free gas in the broad-line region. Our results suggest that the distribution and structure of the obscuring dusty torus are likely to be very complex. We test our results against the smooth and clumpy torus models and find evidence in favor of the clumpy torus model.
Systematic Study of AGN Clumpy Tori with Broadband X-ray Spectroscopy: Updated Unified Picture of AGN Structure
我们提出了使用X射线cluttertorus模型对附近活动星系核（AGN）进行系统的宽带X射线光谱分析的结果（XCLUMPY; Tanimoto et al. 2019）。通过增加本文新分析的16个活动星系核，我们研究了Ichikawa et al.（2015）和García-Bernete et al.（2019）的28个活动星系核，包括未吸收和吸收的活动星系核。这是最大的样品，其X射线和红外光谱分别由cluplantorus模型XCLUMPY和CLUMPY（Nenkova等人，2008）进行分析。根据每个物体的X射线环面参数确定的爱丁顿比和环面覆盖因子之间的关系遵循Ricci等人（2017）基于统计分析发现的趋势。我们证实了Tanimoto等人（2020）的结果：（1）红外数据确定的环面角宽度大于X射线数据确定的环面角宽度;（2）在遮蔽活动星系核中，沿视线方向的氢柱密度与V波段消光比（$N_{\rm H}/A_{\rm V}$）与银河系的平均值相似。未遮蔽的活动星系核的视向$N_{\rm H}/A_{\rm V}$比明显小于银河系的视向比。我们的研究结果可以很好地解释了一个更新的统一的图片AGN结构，包括一个尘埃环，尘埃极地流出，和无尘气体，其中的倾斜度决定了X射线和光学分类和观测到的环面属性在X射线和红外波段。
Chandra Detection of the Circumnuclear Molecular Torus of the Compton Thick AGN in NGC 5643
本文报道了在康普顿厚活动星系核（CT AGN）星系NGC 5643的核区，用深钱德拉ACIS高分辨率的Fe Kα线辐射成像发现的一个星团状拉长特征。此功能可扩展至约65 pc N-S。在3.0-6.0 keV连续区中没有看到相应的特征。Fe Kα特征在空间上与在使用ALMA的CO（2-1）高分辨率成像中发现的N-S伸长一致（Alonso-Herrero et al 2018），但比CO（2-1）线的运动学所指示的r=26 pc的旋转分子盘稍长。Chandra在中性Fe Kα线上探测到了相应的N-S结构，这将证明CO和Fe Kα发射都来自于模糊环。
Nature of Compton-thick Active Galactic Nuclei in "Non-merging'' Luminous Infrared Galaxies UGC 2608 and NGC 5135 Revealed with Broadband X-ray Spectroscopy
How does the Polar Dust affect the Correlation between Dust Covering Factor and Eddington Ratio in Type 1 Quasars Selected from the Sloan Digital Sky Survey Data Release 16?
Hard X-Ray to Radio Multiwavelength SED Analysis of Local U/LIRGs in GOALS Sample with Self-consistent AGN Model Including Polar-dust Component
利用GOALS（Armus et al. 2009）中的核光谱望远镜阵列和/或Swift/Burst Alert望远镜观测到的57个本地发光和超亮红外星系（U/LIRGs），进行了硬X射线-射电多波长光谱能量分布（SED）分解。我们通过实现红外（IR）CLUMPY模型修改了最新的SED拟合程序X-CIGALE，允许自洽地使用X射线环面模型（XCLUMPY）进行多波长研究。采用通过X射线拟合（Yamada et al. 2021）获得的环面参数，我们估计了宿主星系、活动星系核（AGN）环面和极地尘埃的性质。恒星形成率随合并阶段的增加而增大，且大部分在主序以上。SFR与射电光度相关，表明星暴辐射在射电波段占主导地位。虽然极尘消光比环面消光小得多，但极尘的紫外-红外（主要是红外）光度是环面光度的$\sim$ 2倍。极地尘埃的温度降低，而由温度和尘埃升华半径估计的物理尺寸随着活动星系核的光度从几十秒差距（早期合并）到千秒差距尺度（晚期合并）而增加，其中极地尘埃可能是膨胀的（即，不断发展）的尘埃外流。SFR和内禀活动星系核光度的比较表明，星暴发生的第一次和活动星系核出现后，和整体的增长率遵循的同步协同演化关系，可以建立本地星系SMBH质量关系。我们确认共存的强烈的星爆，活动星系核，并在后期的合并大规模外流，支持一个标准的活动星系核反馈方案。
Suzaku View of the Swift/BAT Active Galactic Nuclei. V. Torus Structure of Two Luminous Radio-loud AGNs (3C 206 and PKS 0707-35)
We present the results from broad-band X-ray spectral analysis of 3C 206 and PKS 0707-35 with Suzaku and Swift/BAT, two of the most luminous unobscured and obscured radio-loud active galactic nuclei with hard X-ray luminosities of 10^{45.5} erg s^{-1} and 10^{44.9} erg s^{-1} (14--195 keV), respectively. Based on the radio core luminosity, we estimate that the X-ray spectrum of 3C 206 contains a significant (~ 60% in the 14--195 keV band) contribution from the jet, while it is negligible in PKS 0707-35. We can successfully model the spectra with the jet component (for 3C 206), the transmitted …
