Influence of starforming history on secular heating. The two panels are luminosity fraction of hot orbits heated by secular evolution f_{hot,secular–heated} vs. the cosmic time when the galaxy quenched (upper panel), and vs. the average stellar age of this group of stars (lower panel). All TNG50 massive galaxies (stellar mass M_* ≥ 10^10.5 M_⊙) with quiescent histories (merger ratio of <1:10) are included. For galaxies that are still with star formation at z = 0, we set quench time to be the age of the universe (13.8 Gyr). The Pearson correlation coefficients of the two panels are labeled. Galaxies quenched at an earlier stage are more significantly heated by secular processes, while the average ages of their stars exhibit a weaker correlation.