论文标题

使用新的原子数据集改进了AGN的Fe II排放线模型

Improved Fe II emission line models for AGN using new atomic datasets

论文作者

Sarkar, A., Ferland, G. J., Chatzikos, M., Guzmán, F., van Hoof, P. A. M., Smyth, R. T., Ramsbottom, C. A., Keenan, F. P., Ballance, C. P.

论文摘要

几十年来,了解活跃银河核(AGN)的Fe II发射一直是一个巨大的挑战。理解AGN光谱的回报将是巨大的,涉及类星体分类方案,例如“特征向量1”,并追踪宇宙的化学演化。最近,三个具有辐射和电子碰撞率的大型Fe II原子数据集已获得。我们已经将它们纳入光谱合成代码混浊中,并使用新一代AGN光谱分布(SED)检查预测,这表明根据所使用的数据集,UV发射可能会大不相同。 SMYTH等人的数据集更好地重现了紫外线和光学区域中I ZW 1 Seyfert Galaxy的Fe II模板,我们采用了这些数据。我们考虑热云和微涡轮云,并表明$ \ $ \ $ 100 km/s的微扰动性再现了所谓的Fe II“ UV Bump”的观察到的形状和强度。将我们的预测与观察到的Fe II模板进行比较,我们得出了$ 10^{11} $ cm $^{ - 3} $和$ 10^{20} $ cm $^{ - 2} $ s $ s $ s $^{ - 1} $的典型云密度,并显示了这些很大程度上的fe II ii ii ii sossiess in uv yv and uv yv and uv in uv yv。我们使用最佳拟合型号计算$ i $(fe ii)/$ i $(mg ii)发射线强度比,并获得日志($ i $(fe ii)/$ i $ $(mg ii)$ \ sim $ 0.7,这表明许多AGN的solar fe/mg fe/mg丰度比率大致。最后,我们将爱丁顿的比率和SED形状改变为理解特征向量1相关性的一步。

Understanding the Fe II emission from Active Galactic Nuclei (AGN) has been a grand challenge for many decades. The rewards from understanding the AGN spectra would be immense, involving both quasar classification schemes such as "Eigenvector 1" and tracing the chemical evolution of the cosmos. Recently, three large Fe II atomic datasets with radiative and electron collisional rates have become available. We have incorporated these into the spectral synthesis code Cloudy and examine predictions using a new generation of AGN Spectral Energy Distribution (SED), which indicates that the UV emission can be quite different depending on the dataset utilized. The Smyth et al dataset better reproduces the observed Fe II template of the I ZW 1 Seyfert galaxy in the UV and optical regions, and we adopt these data. We consider both thermal and microturbulent clouds and show that a microturbulence of $\approx$ 100 km/s reproduces the observed shape and strength of the so-called Fe II "UV bump". Comparing our predictions with the observed Fe II template, we derive a typical cloud density of $10^{11}$ cm$^{-3}$ and photon flux of $10^{20}$ cm$^{-2}$ s$^{-1}$, and show that these largely reproduce the observed Fe II emission in the UV and optical. We calculate the $I$(Fe II)/$I$(Mg II) emission-line intensity ratio using our best-fitting model and obtain log($I$(Fe II)/$I$(Mg II)) $\sim$ 0.7, suggesting many AGNs have a roughly solar Fe/Mg abundance ratio. Finally, we vary the Eddington ratio and SED shape as a step in understanding the Eigenvector 1 correlation.

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