Line-of-sight velocity dispersion, ${\sigma }_{v_{los}}$, profiles. Left panel: our quality APOGEE sample (error bar curves) and our mock catalogue (shaded areas of height ±σ). The profiles are plotted for stars with |ℓ|< 2° and |X| < 1.5kpc. Right panel: profiles of our quality APOGEE sample (error bar with circle symbol) and of our mock catalogue (shaded areas of height ±σ), compared to results from Babusiaux et al. (2014) and Babusiaux et al. (2010) (squares), Ness et al. (2013b) (pentagons), Rojas-Arriagada et al. (2014) (triangles), Uttenthaler et al. (2012) (diamonds), and Zoccali et al. (2017) (stars).