2004/03/16 by Alexei Baskin, Ari Laor · 3 citations
Physics and Astronomy · #Active galactic nucleus #Astronomy #Astrophysics #Astrophysics and Cosmic Phenomena #Astrophysics and Star Formation Studies #Galaxies: Formation, Evolution, Phenomena #Galaxy #Physics #astro-ph
paper · pdf · doi:10.1111/j.1365-2966.2004.07833.x
published as Mon.Not.Roy.Astron.Soc. 350 (2004) L31-L35 · Accepted for publication in MNRAS Letters
arxiv created 2004/03/16 · openalex publication_date 2004/04/27 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
The origin of the luminosity dependence of the equivalent width (EW) of broad emission lines in active galactic nuclei (AGN) – the Baldwin effect – is not firmly established yet. We explore this question for the broad C ivλ1549 line using the Boroson & Green sample of the 87 z≤ 0.5 Bright Quasar Survey (BQS) quasars. Useful UV spectra of the C iv region are available for 81 of the objects, which are used to explore the dependence of the C iv EW on various emission properties. We confirm earlier results on the strong correlations of the C iv EW with some of the emission parameters which define the Boroson & Green Eigenvector 1, and with the optical to X-ray slope αox. In addition, we find a strong correlation of the C iv EW with the relative accretion rate, L/LEdd. Since L/LEdd drives some of the Eigenvector 1 correlations, it may be the primary physical parameter which drives the Baldwin effect for C iv.