Signal-to-noise ratio (left panels) and Welch t-test significance (right panels) K_p – V_rest maps for the 2 tested chemical species (top for H₂O, bottom for NH₃) obtained by combining data from the four observing nights excluding spectral orders with ΔS/N < 2 σ. The point where the 2 white dashed lines cross each other is the expected position of a signal with planetary origin.