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arXiv 2104.11263astro-ph.GA
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由X射线和中红外观测得到的尘埃气体AGN环面

The dust-gas AGN torus as constrained from X-ray and mid-infrared observations

Donaji Esparza Arredondo, Omaira González Martín, Deborah Dultzin, Josefa Masegosa, Cristina Ramos Almeida, Ismael García Bernete, Jacopo Fritz, Natalia Osorio Clavijo

摘要:

在过去的几十年里,一些多波长的研究一直致力于探索活动星系核(AGN)中的遮蔽物质的性质。已经开发了各种模型来描述这种材料的结构和分布,并通过光谱拟合技术来约束其物理和几何参数。然而,包括环面中红外(中IR)和X射线发射如何相关的问题仍然没有答案。在这项工作中,我们研究是否在中红外尘埃连续谱和气体的X射线反射有相同的分布在一个样本的活动星系核。我们仔细地选择了一个样本的36个附近的活动星系核与NuSTAR和斯皮策光谱可在这两个档案。我们推导出的核尘埃和气体的性质,通过光谱拟合,使用模型开发的中红外和X射线波长假设光滑和cluquinous分布的这种结构。我们发现,根据赤池标准,对于~80%的具有良好光谱拟合的源,气体和尘埃的平滑和clusterian分布的组合分别是优选的。然而,考虑到每个单独的源的额外信息,如吸收的变化,我们发现,我们的源的~50%是最好的描述由尘埃和气体的clusterian分布。其余的~50%的来源仍然可以用气体的平滑分布和尘埃的聚集分布来解释。结果表明,活动星系核中气体和尘埃的分布是复杂的。我们发现至少有六种情况可以解释我们样本的观测特性。在这些情况下,三种气尘分布组合是可能的:团块状,光滑,光滑团块状。他们中的大多数人都同意的概念,气体也可以位于无尘区,这是一致的灰尘与气体的比例发现。

英文摘要:

In the last decades, several multiwavelength studies have been dedicated to exploring the properties of the obscuring material in active galactic nuclei (AGN). Various models have been developed to describe the structure and distribution of this material and constrain its physical and geometrical parameters through spectral fitting techniques. However, questions, including how the torus mid-infrared (mid-IR) and X-ray emission are related remain unanswered. In this work, we study whether the dust continuum at mid-IR and gas reflection at X-rays have the same distribution in a sample of AGN. We carefully selected a sample of 36 nearby AGN with NuSTAR and Spitzer spectra available in both archives. We derived the properties of the nuclear dust and gas through a spectral fitting, using models developed for mid-IR and X-ray wavelengths assuming smooth and clumpy distributions for this structure. We found that a combination of smooth and clumpy distributions of gas and dust, respectively, is preferred for ~80% of sources with good spectral fits according to the Akaike criterion. However, considering extra information about each individual source, such as the absorption variability, we found that ~50% of our sources are best described by a clumpy distribution of both dust and gas. The remaining ~50% of our sources can still be explained with a smooth distribution of gas and a clumpy distribution of dust. The results presented in this paper suggest that the distribution of the gas and dust in AGN is complex. We find at least six scenarios to explain the observed properties of our sample. In these scenarios, three gas-dust distribution combinations are possible: clumpy-clumpy, smooth-smooth, and smooth-clumpy. Most of them are in agreement with the notion that gas could also be located in the dust-free region, which is consistent with the dust-to-gas ratio found.

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