Upper panel: magenta histogram showing the stellar mass function of the star clumps populating our simulated galaxy. Lower panel: clump sizes (in units of parsec) as a function of the clump stellar mass. Clumps are represented by magenta points. The underlying average size-mass relation given by Eq. (12) (Brown & Gnedin 2021) is shown in a blue solid line. At a given stellar mass, we assume the size distribution follows a lognormal distribution with a standard deviation of σ = 0.3.