THE IONIZING-RADIATION OF SEYFERT-2 GALACTIC NUCLEI

被引：47

作者：

HO, LC ^{[1
]}

SHIELDS, JC ^{[1
]}

FILIPPENKO, AV ^{[1
]}

机构：

[1] OHIO STATE UNIV,DEPT ASTRON,COLUMBUS,OH 43210

来源：

ASTROPHYSICAL JOURNAL | 1993年 / 410卷 / 02期

关键词：

GALAXIES; ABUNDANCES; ACTIVE; NUCLEI; SEYFERT;

D O I：

10.1086/172775

中图分类号：

P1 [天文学];

学科分类号：

0704 ;

摘要：

We report the discovery of a nonrandom trend in the dispersion of emission-line intensity ratios for Seyfert 2 galaxies. The sense of this pattern suggests the influence of a single physical parameter, the hardness of the ionizing continuum (the ratio of X-ray to extreme ultraviolet fluxes), which controls the heating energy per ionizing photon. We compare the observed line ratios with new photoionization calculations and find that the observed distributions can be reproduced if the ionizing continuum is parametrized by a power law, f(nu) is-proportional-to nu(alpha), with alpha ranging from -1 to -2.5. Our results also suggest an inverse correlation between luminosity and continuum hardness for Seyfert 2 nuclei; if true, this trend extends a similar pattern known in quasars and Seyfert 1 galaxies to active galactic nuclei of lower luminosity. Samples of Seyfert 2 nuclei with improved selection uniformity are desirable for elaboration of these findings.

引用

页码：567 / 573

页数：7

共 41 条

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