Spatial distribution of star formation rate averaged over different timescales. Left three panels: Surface density distributions of star formation rate averaged over the last 10⁷, 10⁸ and 10⁹ yr (i.e., the birth mass of stars younger than the age limits divided by the age limits), respectively. The black contours overplotted in the left three panels correspond to 50% of the maximum Σ_SFR. Rightmost panel: Surface density distribution of stellar mass.