Investigating the nuclear obscuration in two types of Seyfert 2 galaxies

	Investigating the nuclear obscuration in two types of Seyfert 2 galaxies
	Shu, X. W.; Wang, J. X.; Jiang, P.; Fan, L. L.; Wang, T. G.
刊名	ASTROPHYSICAL JOURNAL
	2007-03-01
卷号	657 期号:1 页码:167-176
关键词	galaxies : active galaxies : Seyfert polarization
英文摘要	We build a large sample of Seyfert 2 galaxies (Sy2s) with both optical spectropolarimetric and X-ray data available, in which 29 of the Sy2s have a detection of polarized broad emission lines (PBLs) and 25 do not. We find that for luminous Sy2s with L-[O III] > 10(41) ergs s(-1), sources with PBLs have smaller X-ray absorption column densities in comparison to those without PBLs (at a 92.3% confidence level): most of the Sy2s with N-H < 10(23.8) cm(-2) show PBLs (86%; 12 out of 14), while the fraction is much smaller for sources with heavier obscuration (54%; 15 out of 28). The confidence level of the difference in absorption bounces up to 99.1% when using the thickness ("T'') ratio (F2-10 keV/F-[O III]) as an indicator. We rule out observation or selection bias as the origin for the difference. Our results, for the first time with high statistical confidence, show that, in additional to the activity of the nuclei, the nuclear obscuration also plays an important role in the visibility of PBLs in Sy2s. These results can be interpreted in the framework of the unified model. We can reach these results in the unified model if (1) the absorption column density is higher at large inclinations and (2) the scattering region is obscured at large inclinations.
WOS标题词	Science & Technology ; Physical Sciences
类目[WOS]	Astronomy & Astrophysics
研究领域[WOS]	Astronomy & Astrophysics
关键词[WOS]	ACTIVE GALACTIC NUCLEI ; ULTRALUMINOUS INFRARED GALAXIES ; XMM-NEWTON OBSERVATIONS ; BROAD-LINE REGIONS ; X-RAY-EMISSION ; CIRCINUS GALAXY ; OPTICAL SPECTROSCOPY ; STARBURST GALAXIES ; NEARBY SEYFERT ; UNIFIED MODEL
收录类别	SCI
语种	英语
WOS记录号	WOS:000244635300015
内容类型	期刊论文
源URL	[http://119.78.226.72/handle/331011/19498]
专题	上海天文台_星系宇宙学重点实验室
作者单位	1.Univ Sci & Technol China, Ctr Astrophys, Hefei 230026, Peoples R China 2.Univ Sci & Technol China, Joint Inst Galaxy & Cosmol, Hefei 230026, Peoples R China 3.Chinese Acad Sci, Shanghai Astron Observ, Beijing 100864, Peoples R China
推荐引用方式 GB/T 7714	Shu, X. W.,Wang, J. X.,Jiang, P.,et al. Investigating the nuclear obscuration in two types of Seyfert 2 galaxies[J]. ASTROPHYSICAL JOURNAL,2007,657(1):167-176.
APA	Shu, X. W.,Wang, J. X.,Jiang, P.,Fan, L. L.,&Wang, T. G..(2007).Investigating the nuclear obscuration in two types of Seyfert 2 galaxies.ASTROPHYSICAL JOURNAL,657(1),167-176.
MLA	Shu, X. W.,et al."Investigating the nuclear obscuration in two types of Seyfert 2 galaxies".ASTROPHYSICAL JOURNAL 657.1(2007):167-176.