Narrow line Seyfert 1 galaxies: where are the broad line regions?

• Published in: Science China. Physics, mechanics & astronomy Vol. 53; no. 12; pp. 2307 - 2311
• Main Authors: Mao, WeiMing, Hu, Chen, Wang, JianMin, Bian, WeiHao, Zhang, Shu, Zhao, Gang
• Format: Journal Article
• Language: English
• Published: Heidelberg SP Science China Press 01.12.2010; Springer Nature B.V
• Subjects: Astronomy; Classical and Continuum Physics; Observations and Techniques; Physics; Physics and Astronomy; Research Paper; Reverberation; Seyfert galaxies; Sky surveys (astronomy); Toruses; black hole physics; galaxies: evolution; quasars: general
• ISSN: 1674-7348; 1869-1927
• DOI: 10.1007/s11433-010-4158-z

A sample consisting of 211 narrow line Seyfert 1 galaxies (NLS1s) with high quality spectra from the Sloan Digital Sky Survey (SDSS) is selected to explore where broad line regions are in these objects. We find that the H β profile can be fitted well by three (narrow, intermediate and broad) Gaussian components, and the FWHM ratios of the broad to the intermediate components hold a constant of 3.0 roughly for the entire sample. If the broad components originate from the region scaled by the well-determined H β reverberation mapping relation, we find that the intermediate components originate from the inner edge of the torus, which is scaled by dust K -band reverberation. We find that the IC and the BC are strongly linked dynamically, but the relation of their covering factors is much more relaxed, implying that both regions are clumpy.