Mass – size relations for ATLAS^3D fast (bottom) and slow (top) rotators. In both panels, small open symbols show galaxies with no HST imaging, and small filled symbols represent galaxies with uncertain light profiles. The colour specifies core (red) and core-less galaxies (light blue). Symbols refer to kinematic classes defined in Krajnović et al. (2011, see also Table 3), including KDC, CRC, 2σ, LV, NRR, and RR. Vertical lines are drawn at characteristic masses of 0.8 and 2 × 10¹¹ M_⊙. Constant velocity dispersions are shown by dashed lines. Compared to Fig. 6 of Krajnović et al. (2013b), the new HST data show that core galaxies do not appear in galaxies less massive than 0.8 × 10¹¹ M_⊙, and that all slow rotators more massive than 10¹¹ M_⊙ have cores. The black symbol in the top panel is NGC 1222.