The Origin of Fe II and [Fe II] Emission Lines in the 4000-10000 Å Range in the BD Weigelt Blobs of η Carinae
The Origin of Fe II and [Fe II] Emission Lines in the 4000-10000 Å Range in the BD Weigelt Blobs of η Carinae
复制标题
η Carinae BD Weigelt Blob 中 4000-10000 Å 范围内 Fe II 和 [Fe II] 发射线的起源
DOI：
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发表时间：
2002
期刊：
影响因子：
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通讯作者：
K. Davidson
中科院分区：
文献类型：
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作者：
E. Verner;T. Gull;F. Bruhweiler;S. Johansson;K. Ishibashi;K. Davidson
我们提出的数值模拟再现的显着特点，令人惊讶的强[Fe II]和Fe II的发射光谱中的B和D Weigelt斑点的船底座η。在我们的研究中，我们使用了哈勃太空望远镜（HST）在1998年观测期间获得的光谱。B和D Weigelt斑点的光谱在[Fe II]和Fe II发射线中占主导地位。同样的观察结果显示没有Fe I或Fe III。我们比较了我们的测量最强（≥200）[Fe II]和Fe II线和混合物的光谱与理论预测。我们的预测是基于Fe II原子的非LTE建模，其中包括最低的371个能级（所有能级高达11.6 eV）。我们研究了光谱对电子密度的依赖性、类黑体恒星连续谱的抽运和强的Lyα发射。我们发现，辐射泵浦是必不可少的解释所观察到的光谱。我们已经确定了负责所观察到的Fe II排放的主要泵送路线。模型和观测结果的比较揭示了辐射场的细节。来自船底座η星的类黑体辐射场的抽运解释了在4000-6500 nm范围内的大量强[Fe II]和Fe II线。在8000-10000 μ m范围内最强的Fe II线是由强的Lyα辐射泵浦的。
We present numerical simulations that reproduce the salient features of the amazingly strong [Fe II] and Fe II emission spectra in the B and D Weigelt blobs of η Carinae. For our studies we have used spectra obtained during the 1998 epoch observations with the Hubble Space Telescope (HST). The spectrum of the B and D Weigelt blobs dominates in [Fe II] and Fe II emission lines. The same observations show no Fe I or Fe III. We have compared our measurements of the strongest (≥200) [Fe II] and Fe II lines and blends in the spectrum with theoretical predictions. Our predictions are based on non-LTE modeling of the Fe II atom, which includes the lowest 371 energy levels (all levels up to 11.6 eV). We have investigated the dependence of the spectrum on electron density, pumping by the blackbody-like stellar continuum, and intense Lyα emission. We find that radiative pumping is essential in explaining the observed spectrum. We have identified the main pumping routes responsible for the observed Fe II emission. Comparison between the model and observations reveals details of the radiation field. Pumping by the blackbody-like stellar radiation field from η Carinae explains the numerous strong [Fe II] and Fe II lines in the range of 4000-6500 Å. The strongest Fe II lines in a range of 8000-10000 Å are pumped by intense Lyα radiation.