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Paper: AGN Emission-Line Properties vs. Eddington Ratio
Volume: 311, AGN Physics with the Sloan Digital Sky Survey
Page: 103
Authors: Warner, C.; Hamann, F.; Dietrich, M.
Abstract: We analyze UV spectra for a large sample of 578 Active Galactic Nuclei and derive Eddington ratios, L/Ledd, from bolometric luminosities and emission line widths for each object in the sample. We include a sample of 26 Narrow-Line Seyfert 1s (NLS1s) for comparative analysis. The sample spans five orders of magnitude in supermassive black hole (SMBH) mass, seven orders of magnitude in luminosity, and a redshift range from 0 ≤ z ≤ 5. Composite spectra sorted by L/Ledd show an unusual emission-line behavior: nearly constant peak heights and decreasing FWHMs with increasing L/Ledd. The origins of this unusual behavior with L/Ledd are not understood, but one implication it is that metallicity estimates based on trends in emission line ratios involving nitrogen show no trend with L/Ledd in the composite spectra created from different ranges in L/Ledd. The NLS1 composite, however, shows an unusually high metallicity for its SMBH mass and luminosity. We conclude that if SMBH mass is related to the fundamental parameter affecting metallicity in the broad emission line region (BLR), then there must be some secondary effect that is enhancing the metallicity in NLS1s.
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