Posterior distributions of v_broad from simulated data with different noise levels. The noise level corresponds to that of the observed spectra multiplied by the factor that is reported at the top of each panel. The simulated broadening of 2 km s⁻¹ can be retrieved for noise levels up to ten times that of the simulated observation data. The median and 1σ percentiles of the distributions that retrieve the simulated line broadening are indicated by the dashed vertical lines.