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arXiv 1101.0189astro-ph.CO
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Swift/BAT活动星系核的朱雀视图。III。数值环面模型在两个近康普顿厚活动星系核(NGC 612和NGC 3081)中的应用

Suzaku View of the Swift/BAT Active Galactic Nuclei. III. Application of Numerical Torus Models to Two Nearly Compton Thick AGNs (NGC 612 and NGC 3081)

Satoshi Eguchi, Yoshihiro Ueda, Hisamitsu Awaki, James Aird, Yuichi Terashima, Richard Mushotzky

摘要:

本文研究了由朱雀星跟踪观测获得的两个Swift/BAT活动星系核的宽带光谱:NGC 612和NGC 3081。用标准模型进行拟合,发现两个光源的光谱相似,其特征是对$N_{\rm{H}} \simeq 10^{24} \ \rm{cm}^{-2}$有很强的吸收,散射光的分量为$f_{\rm{scat}} = 0.5-0.8%$,反射分量的立体角为$Ω/2π= 0.4-1.1$。为了研究环面的几何形状,我们将Ikeda等人(2009)利用蒙特卡罗模拟的数值光谱模型应用于朱雀光谱。我们发现我们的数据很好地解释了这个环面模型,它有四个几何参数。拟合结果表明,NGC 612的环面半张角为$\simeq 60^{\circ}-70^{\circ}$,并且是从一个接近边缘的角度观察到的,有少量的散射气体,而NGC 3081的张角$\simeq 15^\circ$非常小,并且是从一个正面的几何形状观察到的,更像是Ueda等人(2007)发现的深埋的“新型”活动星系核。我们展示了直接应用这种数值模拟的潜在力量,以高质量的宽带光谱,揭示活动星系核的内部结构。

英文摘要:

The broad band spectra of two Swift/BAT AGNs obtained from Suzaku follow-up observations are studied: NGC 612 and NGC 3081. Fitting with standard models, we find that both sources show similar spectra characterized by a heavy absorption with $N_{\rm{H}} \simeq 10^{24} \ \rm{cm}^{-2}$, the fraction of scattered light is $f_{\rm{scat}} = 0.5-0.8%$, and the solid angle of the reflection component is $Ω/2π= 0.4-1.1$. To investigate the geometry of the torus, we apply numerical spectral models utilizing Monte Carlo simulations by Ikeda et al. (2009) to the Suzaku spectra. We find our data are well explained by this torus model, which has four geometrical parameters. The fit results suggest that NGC 612 has the torus half opening-angle of $\simeq 60^{\circ}-70^{\circ}$ and is observed from a nearly edge-on angle with a small amount of scattering gas, while NGC 3081 has a very small opening angle $\simeq 15^\circ$ and is observed on a face-on geometry, more like the deeply buried "new type" AGNs found by Ueda et al. (2007). We demonstrate the potential power of direct application of such numerical simulations to the high quality broad band spectra to unveil the inner structure of AGNs.

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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