Oscillation height H_max (ppm² μHz⁻¹) as a function of the frequency at maximum amplitude ν_max (μHz) of the 4465 red giants considered in this work, minus the 30 for which no oscillations were detected, that is 4435 total. The parameter H_max is the height of the Gaussian function used to fit the oscillation contribution to the power spectral density. The frequency at maximum amplitude ν_max is the center of the same Gaussian function. Light gray points indicate all the targets, green are l = 1 depleted, red squares are the systems with significant surface activity, and blue circles indicate the cases of ambiguous detection of surface activity.