Age vs. mass fraction (bottom) and light fraction (top) of the stellar populations synthesized in the fitting of the spectrum of the X-shaped source J1201-0703. The squares correspond to stellar populations with different metallicities (in the color version: orange 1.0 Z_⊙ and red 2.5 Z_⊙). The solid curve represents Gaussian smoothing of the mass fraction and light fraction distributions. The resulting peaks or bursts of star formation are marked with a star.