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Paper: What is the Origin of the Baldwin Effect in the BLR and the NLR?
Volume: 311, AGN Physics with the Sloan Digital Sky Survey
Page: 175
Authors: Baskin, A.; Laor, A.
Abstract: The origin of the luminosity dependence of the strength of broad and narrow emission lines in AGN (i.e., the Baldwin effect) is not firmly established yet. We explore this question using the Boroson & Green sample of the 87 z ≤ 0.5 PG quasars. UV spectra of the C IV region with a sufficient S/N are available for 81 of the objects. We use these spectra to explore the dependence of the C IV EW on MBH and L/LEdd, as deduced from optical spectra of the Hβ region. We find a strong correlation of the C IV EW with L/LEdd. This may be the primary correlation which drives the Baldwin effect for C IV. A similar correlation analysis using the C IV FWHM instead of the Hβ FWHM, yields an insignificant correlation. This suggests that the C IV FWHM provides a significantly less accurate estimate of MBH compared to the Hβ FWHM. We also measured the [O III] λ4363/[O III] λ5007 line ratio for 72 objects in this sample, and use it to determine whether density or covering factor control the large range in [O III] λ5007 strength in AGN.
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