Are the Nuclei of Seyfert 2 Galaxies Viewed Face-On?
Are the Nuclei of Seyfert 2 Galaxies Viewed Face-On?
复制标题
Seyfert 2 星系的核心是正面观察的吗？
DOI：
10.1086/311527
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发表时间：
1998
期刊：
影响因子：
--
通讯作者：
C. Reynolds
中科院分区：
文献类型：
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作者：
K. Weaver;C. Reynolds
通过对四个x射线明亮窄发射线星系（Seyfert型1.9和2）的ASCA光谱中的Fe - k - α线进行建模，我们发现两个同样可行的物理模型可以描述观测到的谱线轮廓。第一种由Turner等人讨论，由近极上吸积盘的发射组成。第二种，在统计上更受欢迎，是在~48°的中间倾角上观察到的吸积盘发射的叠加，以及一个明显的，未解决的特征，可能起源于距离星系核一定距离的地方。中间倾角与统一方案完全一致，我们的发现挑战了最近的断言，即Seyfert 2星系优先从其内部区域正面观察。我们分别推导⟨EWN⟩=60 eV和⟨EWD⟩=213 eV的窄线和盘线的平均等效宽度。x射线数据很好地描述了一种几何结构，在这种几何结构中，我们对活动核的观察与隐蔽环面的外缘相交并被遮挡，因此不需要吸积盘和环面的严重错位。
We show from modeling the Fe Kα line in the ASCA spectra of four X-ray-bright narrow emission line galaxies (Seyfert types 1.9 and 2) that two equally viable physical models can describe the observed line profile. The first is discussed by Turner et al. and consists of emission from a nearly pole-on accretion disk. The second, which is statistically preferred, is a superposition of emission from an accretion disk viewed at an intermediate inclination of ~48° and a distinct, unresolved feature that presumably originates some distance from the galaxy nucleus. The intermediate inclination is entirely consistent with unified schemes, and our findings challenge recent assertions that Seyfert 2 galaxies are preferentially viewed with their inner regions face-on. We derive mean equivalent widths for the narrow and disk lines of ⟨EWN⟩=60 eV and ⟨EWD⟩=213 eV, respectively. The X-ray data are well described by a geometry in which our view of the active nucleus intersects and is blocked by the outer edges of the obscuring torus and therefore do not require severe misalignments between the accretion disk and the torus.