Correlation between Eddington Ratios and Broad-Line Luminosities in Flat-Spectrum Radio Quasars, BL Lacertae Objects, and Radio Galaxies

• Published in: The Astronomical journal 2007-05, Vol.133 (5), p.2187-2191
• Main Authors: Dai, H, Xie, G. Z, Zhou, S. B, Li, H. Z, Chen, L. E, Ma, L
• Format: Article
• Language: English
• ISSN: 1538-3881; 0004-6256; 1538-3881
• DOI: 10.1086/511769

We compiled a sample of 16 flat-spectrum radio quasars (FSRQs), 8 BL Lac objects, and 15 Fanaroff-Riley (FR) I and FR II radio galaxies, for which the intrinsic Eddington ratios and broad-line luminosities are available. In the diagram of the intrinsic Eddington ratio-broad-line luminosity relation, FSRQs are found in the high broad-line luminosity, high intrinsic Eddington ratio region, while BL Lac objects, as well as FR I and FR II radio galaxies, are found in the low broad-line luminosity, low intrinsic Eddington ratio region. In addition, the intrinsic Eddington ratios are strongly correlated with the broad-line luminosities and also with the intrinsic bolometric luminosities, but the correlation with the broad-line luminosities is better. Thus, the broad-line luminosity, rather than the intrinsic bolometric luminosity, should be used as a fundamental parameter of the unified scheme and evolution of active galactic nuclei. On the other hand, we analyze the theory proposed by Czerny and coworkers that the formation of the broad-line region (BLR) is intrinsically connected to the existence of a cold accretion disk. Our studies support that BLR formation is intimately connected with the cold disk. Thus, our results provide solid experimental evidence for the theory that has been proposed by Czerny and coworkers.