Parameter uncertainties in single-component Gaussian fits to spectra containing one Gaussian. The shaded regions show the error distributions for the estimated parameters as a function of the relative noise 1-30%. The grey, blue, and red colours correspond to [0.01, 99.9], [10, 90], and [25, 75] percentile intervals, respectively. The solid black line shows the median estimates. The solid white lines correspond to the mean 1-σ error estimates (plotted relative to the true values), as obtained from 100 Monte Carlo samples. The white shaded regions correspond to the 1-σ dispersion of the error estimates between spectra at the same noise level.