The 2-D CCF(τ,v) shows the correlation of the Hβ line segment light curves with the continuum light curve at 5180 Å as a function of velocity and time delay (grey scale). Contours of the correlation coefficient are overplotted at levels of 0.93, 0.89, and 0.80 (solid lines). The heavy dashed line connects the centers of all individual cross-correlation functions.