Results of simulations testing the ability of our pipeline to successfully recover a velocity dispersion of different values at low S/N (per pixel) levels, from S/N = 5–10 (left panel), S/N = 10–15 (middle panel), up to S/N = 15–20 (right panel). Shaded areas correspond to the standard deviation of the measured values at every S/N. The red solid line corresponds to the output values equal to the input ones (unity line). In this experiment, the error is dominated by Poisson noise and no systematic sources of uncertainties have been considered. See Appendix D.1 for details.