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arXiv 2406.08720astro-ph.GA
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具有含尘/无尘气体结构的活动星系核的更新图景及辐射压力效应

Updated Picture of the Active Galactic Nuclei with Dusty/Dust-free Gas Structures and Effects of the Radiation Pressure

Shoichiro Mizukoshi, Takeo Minezaki, Hiroaki Sameshima, Mitsuru Kokubo, Hirofumi Noda, Taiki Kawamuro, Satoshi Yamada, Takashi Horiuchi

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16 pages, 9 figures, accepted for publication in MNRAS
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AI总结：

该研究利用尘埃消光和柱密度区分AGN含尘与无尘气体，发现高爱丁顿比下二者覆盖因子均下降，并据此提出辐射压力等机制作用下的AGN气体结构新图景。

摘要：

本研究通过视线方向尘埃消光（$A_V$）和中性气体柱密度（$N_{\mathrm{H}}$）对X射线选活动星系核（AGNs）的两种气体结构，即含尘气体成分和无尘气体成分进行分离，并研究其性质。含尘气体和无尘气体的典型柱密度随Seyfert类型而不同，表明这两种结构都具有各向异性的柱密度分布。含尘气体柱密度（$N_{\mathrm{H,d}}$）满足$\log N_{\mathrm{H,d}}\\ [\mathrm{cm^{-2}}]>23$的目标数量，远少于无尘气体具有相同柱密度的目标数量。该结果表明，含尘气体结构的光厚部分非常薄。爱丁顿比（$f_{\mathrm{Edd}}$）大于含尘气体有效爱丁顿极限的目标非常少，而且满足$22\leq \log N_{\mathrm{H,d}}\\ [\mathrm{cm^{-2}}]<24$的含尘气体的覆盖因子在有效爱丁顿极限处表现出明显下降。这些结果支持如下情景：在高爱丁顿比下，由于辐射驱动的含尘气体外流，尘埃环的覆盖因子会降低。柱密度（$N_{\mathrm{H,df}}$）满足$22\leq \log N_{\mathrm{H,df}}\\ [\mathrm{cm^{-2}}]<24$的无尘气体的覆盖因子同样在高爱丁顿比下表现出下降，尽管这可能是由辐射压力之外的某些其他机制驱动的无尘气体外流所致。最后，我们基于本文结果和已有文献提出了一个关于AGN气体结构的更新图景。

英文摘要：

This study investigates the properties of two gas structures of X-ray selected active galactic nuclei (AGNs), that is, dusty and dust-free gas components, by separating them with the line-of-sight dust extinction ($A_V$) and the neutral gas column density ($N_{\mathrm{H}}$). The typical column density of the dusty and dust-free gas differs depending on the Seyfert type, indicating that both structures have anisotropic column density distributions. The number of targets with the dusty gas column density ($N_{\mathrm{H,d}}$) of $\log N_{\mathrm{H,d}}\ [\mathrm{cm^{-2}}]>23$ is much smaller than that with the same column density of the dust-free gas. This result indicates that the optically-thick part of the dusty gas structure is very thin. There are very few targets with a larger Eddington ratio ($f_{\mathrm{Edd}}$) than the effective Eddington limit of the dusty gas and the covering factor of the dusty gas with $22\leq \log N_{\mathrm{H,d}}\ [\mathrm{cm^{-2}}]<24$ exhibits a clear drop at the effective Eddington limit. These results support the scenario wherein the covering factor of the dusty torus decreases in a high Eddington ratio owing to the radiation-driven dusty gas outflow. The covering factor of the dust-free gas with the column density ($N_{\mathrm{H,df}}$) of $22\leq \log N_{\mathrm{H,df}}\ [\mathrm{cm^{-2}}]<24$ similarly exhibits the decrease in high Eddington ratio, although it may be owing to the dust-free gas outflow driven by certain other mechanisms than the radiation pressure. Finally, we propose an updated picture of the AGN gas structure based on our results and the literature.

机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。

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