Are the nuclei of Seyfert 2 galaxies viewed face-on?

被引:37
作者
Weaver, KA
Reynolds, CS
机构
[1] Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA
[2] Univ Colorado, JILA, Boulder, CO 80309 USA
基金
美国国家科学基金会;
关键词
galaxies : active; galaxies : nuclei; galaxies : Seyfert; X-rays : galaxies;
D O I
10.1086/311527
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
We show from modeling the Fe K alpha 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 similar to 48 degrees 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.
引用
收藏
页码:L39 / L43
页数:5
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