Observationally , it has been reported that the densest stellar system in the Universe does not exceed a maximum stellar surface density , \Sigma ^ { \max } _ { * } = 3 \times 10 ^ { 5 } M \textsubscript \odot pc ^ { -2 } , throughout a wide physical scale ranging from star cluster to galaxy .
This suggests there exists a fundamental physics which regulates the star formation and stellar density .
However , factors that determine this maximum limit are not clear .
In this study , we show that \Sigma ^ { \max } _ { * } of galaxies is not a constant as previous work reported , but actually depends on the stellar mass .
We select galaxy sample from the Sloan Digital Sky Survey Data Release 12 at z = 0.01 - 0.5 .
In contrast to a constant maximum predicted by theoretical models , \Sigma ^ { \max } _ { * } strongly depends on stellar mass especially for less massive galaxies with \sim 10 ^ { 10 } M \textsubscript \odot .
We also found that a majority of high- \Sigma _ { * } galaxies show red colours and low star-formation rates .
These galaxies probably reach the \Sigma ^ { \max } _ { * } as a consequence of the galaxy evolution from blue star forming to red quiescent by quenching star formation .
One possible explanation of the stellar-mass dependency of \Sigma ^ { \max } _ { * } is a mass dependent efficiency of stellar feedback .
The stellar feedback could be relatively more efficient in a shallower gravitational potential , which terminates star formation quickly before the stellar system reaches a high stellar density .