论文标题
类星体中的Fe III发射：致密湍流介质的证据
Fe III emission in quasars: evidence for a dense turbulent medium
论文作者
论文摘要
原子能级数据的最新改进允许在发光的光谱中对Fe III线发射强度进行准确的预测，$ l_ \ text {bol} = 10^{46} -10} -10^{48} $ erg/s，$ erg/s，活跃的半乳酸核。 Fe III发射气体必须主要进行光电离，这与线条混响的观察一致。我们使用探索广泛参数空间的多云模型，以及从斯隆数字天空调查中的26,500个REST框架紫外光谱，以限制发射气体的物理条件。观察到的Fe III排放最好由密度（$ n_h = 10^{14} $ cm $^{ - 3} $）的气体来解释，该气体是微涡轮的，导致线条光学深度和荧光激发。如此高密度的气体似乎存在于大多数发光类星体的中央区域。使用我们喜欢的模型，我们介绍了Fe III UV34 $λλ$ 1895,1914,1926多重的相对强度的理论预测。当使用这些线以推断出有关类星体的宽线区域的物理信息时，必须将此多重组与SI III] $λ$ 1892和CIII $ 1892和CIII] $λ$ 1909的发射线混合在一起。
Recent improvements to atomic energy-level data allow, for the first time, accurate predictions to be made for the Fe III line emission strengths in the spectra of luminous, $L_\text{bol}=10^{46}-10^{48}$ erg/s, Active Galactic Nuclei. The Fe III emitting gas must be primarily photoionized, consistent with observations of line reverberation. We use CLOUDY models exploring a wide range of parameter space, together with 26,500 rest-frame ultraviolet spectra from the Sloan Digital Sky Survey, to constrain the physical conditions of the line emitting gas. The observed Fe III emission is best accounted for by dense ($n_H=10^{14}$ cm$^{-3}$) gas which is microturbulent, leading to smaller line optical depths and fluorescent excitation. Such high density gas appears to be present in the central regions of the majority of luminous quasars. Using our favoured model, we present theoretical predictions for the relative strengths of the Fe III UV34 $λλ$1895,1914,1926 multiplet. This multiplet is blended with the Si III] $λ$1892 and C III] $λ$1909 emission lines and an accurate subtraction of UV34 is essential when using these lines to infer information about the physics of the broad line region in quasars.
