More Variable Quasars Have Stronger Emission Lines

UV/optical variation, likely driven by accretion disk turbulence, is a defining characteristic of type 1 active galactic nuclei and quasars. In this work we investigate an interesting consequence such turbulence using quasars in Sloan Digital Sky Survey Stripe 82 for which the measurements variability amplitude are available from ∼10 yr long light curves. We discover positive correlations between σrms equivalent widths C iv, Mg ii, [O iii]5007 emission lines. Such remain statistically robust through partial correlation analyses, i.e., after controlling effects other variables including bolometric luminosity, central supermassive black hole mass, Eddington ratio, redshift. This, first time, indicates causal link line production. propose two potential underlying mechanisms, both may be involved: (1) with stronger have on average bluer/harder broadband spectral energy distribution, expected effect thermal fluctuation model; (2) could lead to launch regions larger covering factors.