In quiescent galaxies, secular mass evolution results in consistent orbital evolution and largely established mass gradients. The slopes of the velocity curves can be considered as the drift slopes of the stars. The data presented in Figure 3.1 [14] reveal that all the log-slopes of the rotation curve of the Milky Way galaxy are greater than negative unity (). The inner zones of galaxies containing massive blackholes typically exhibit a log-slope of the negative half (), such as the Milky Way galaxy [14].

Figure 3.1 – Logarithmic velocity gradients of Milky Way galaxy (based on reference [14])