Published online by Cambridge University Press: 24 November 2004
An increasing number of AGNs exhibit broad, double-peaked Balmer emission lines, which arise from the outer regions of the accretion disk which fuels the AGN. The line profiles vary on timescales of 5–10 years. Our group has monitored a set of 20 double-peaked emitters for the past 8 years (longer for some objects). Here we describe a project to characterize the variability patterns of the double-peaked Hα line profiles and compare with those of two simple models: a circular disk with a spiral arm and an elliptical disk.