Comparison of the stellar velocity distribution σ_* computed by Chilingarian et al. (2017) with the gas velocity distribution σ_gas for the NBCS and the velocity distribution of the single Gaussian approximation σ_single for the DPS. We show in red (resp. black) points the median and the 68% quantile for a binning according to σ_* of the DPS (resp. NBCS). For the DPS, the limitations in σ_1, 2 and Δv_DP of the double Gaussian fit are restricted by the spectral resolution (see Sect. 2.2.2), leading to a restriction of a minimal σ_single, indicated with a red line. We also show the minimal σ_gas for the NBCS as a black line and the best fit of a linear function as a black dashed line.