Top panels: Infall time distributions. The grey histograms represent all the galaxies, and the dashed and solid curves represent the results of GMM fitting, which yields six Gaussian components. The t_fall distributions of the six orbital populations are shown as red histograms. These curves roughly align with the six Gaussian components, which are highlighted as red dashed curves one by one for visual clarity. Rows 2 to 4: Number distributions, median t_fall distributions, and RMSE_pix distributions in the R − V diagram of the six orbital populations.