论文标题
[n ii] $λλ$ 6548，6583Å线的通量比在活性银河核2型样品中
The flux ratio of the [N II]$λλ$ 6548, 6583 Å lines in sample of Active Galactic Nuclei Type 2
论文作者
论文摘要
在活性银河核（AGN）的光谱中，[n ii] 6548，6583 A线通常使用这两条线的固定强度比（r [n ii] = i $ _ {6583} $/I $ _ {6548} $）。但是，固定强度比的使用值通过文献略有不同。过渡概率有几种理论计算，可用于线比估计，但是对该比率没有实验测量，因为[n II]线在实验室等离子度中极为弱。因此，[N II]线的强度比只能在天体物理对象的光谱中测量。但是，由于在各种光谱中的[N II]比率的测量困难（与H $α$重叠，[N II]的弱强度，连续噪声和流出贡献的影响等），精确的和系统的测量尚未进行。在这里，我们介绍了[n ii] $λλ$ 6548，6583的通量比的测量值，用于250型2型AGNS光谱的样品的发射线，以Sloan数字天空调查（SDSS）数据库形式。选择该光谱具有高信噪比和[n II]，而H $α$线不会重叠。从测量值获得的平均通量比为3.049 $ \ pm $ 0.021。我们的结果与考虑到磁性偶极子操作员的相对论校正获得的理论结果一致。
In spectra of the Active Galactic Nuclei (AGNs), the [N II] 6548, 6583 A lines are commonly fitted using the fixed intensity ratio of these two lines (R[N II]=I$_{6583}$/I$_{6548}$). However, the used values for fixed intensity ratio are slightly different through literature. There are several theoretical calculations of the transition probabilities which can be used for the line ratio estimation, but there are no experimental measurements of this ratio, since the [N II] lines are extremely weak in laboratory plasma. Therefore, the intensity ratio of [N II] lines can be measured only in the spectra of astrophysical objects. However, precise and systematic measurements have not be done so far, because of difficulties in measurement of the [N II] ratio in various spectra (overlapping with H$α$, weak intensity of [N II], influence of the continuum noise and outflow contribution, etc.). Here we present the measurements of the flux ratio of the [N II]$λλ$ 6548, 6583 A emission lines for a sample of 250 Type 2 AGNs spectra taken form Sloan Digital Sky Survey (SDSS) data base. The spectra are chosen to have high signal-to-noise ratio and to [N II] and H$α$ lines do not overlap. The obtained mean flux ratio from measurements is 3.049 $\pm$ 0.021. Our result is in agreement with theoretical result obtained by taking into account the relativistic corrections to the magnetic dipole operator.
