$M_{\text{galaxy}}^{\text{stellar}}$ versus $M_{\text{BH}}/M_{\text{NSC}}^{\text{stellar}}$. The 2D PDF is shown as contour lines; the thick solid line marks the 1σ of the 2D PDFs. The best fit of the data is represented by dashed lines. From left to right, the contours indicate model A2 (light rose), A3 (blue), A4 (red), A7 (cyan), A8 (purple), D3 (orange), D4 (green), D7 (brown), and D8 (teal), while black lines correspond to the observational sample. The filled light areas correspond to the 1σ error of the fit slope and intercept.