Typical CCF_DI integrated over the disk of WASP-121 (blue points, obtained during one of the out-of-transit exposures in Visit 2). The solid black profile is the best-fit double-Gaussian model to the measured CCF. The dashed black profiles show the individual Gaussian components to this model, which yields a low dispersion on the fit residual (bottom panel). The blue shaded regions indicate the velocity ranges used to define the CCF continuum.