Illustration of our automated noise estimation routine for a mock spectrum containing two signal peaks and a negative noise spike. Hatched red areas indicate spectral channels that are masked out and hatched blue areas indicate all remaining spectral channels used in the noise calculation. Right panel: Comparison of the true noise value (σ_{rms,  true}; black dash-dotted lines) with the noise value estimated by our automated routine (σ_rms, blue solid lines). See Sect. 3.1.1 for more details.