Detection percentage p(λ₁ ) as a function of the maximum linear frequency shift |Max (δν)|_L obtained from 100 realizations of each simulated spectrum (see Sect. 4.2). Each solid line corresponds to a given (color-coded) level of noise σ₀. The opened red circles correspond to the Kepler stars which successfully passed the selection criterion λ₁ , while the filled red circles indicate the stars which passed the selection criterion λ₂ as well (see Sect. 5). The y coordinate of each star represents the percentage p(λ₁ ) of being detected according to the simulations. The horizontal dashed line indicates the 50% detection threshold.