UV diagnostic diagrams with observation of individual sources and stacks from VUDS. The large yellow-filled circle, square, and pentagon show the VUDS composites of the strong [CIII] emitters (EW([CIII]) > 20 Å, Sample A), the intermediate [CIII] emitters (EW([CIII]) = 10–20 Å, Sample B), and all star-forming galaxies identified by VUDS (Sample C), respectively (Le Fèvre et al. 2017; see Table 2). The smaller black open circles and squares are the individual VUDS objects in samples A and B, respectively, whose [CIII] is identified at the >5σ significance level (Le Fèvre et al. 2017). The VUDS objects marked with a red diamond are type-II AGN candidates. The green crosses show metal-poor compact galaxies found by VUDS (Amorín et al. 2017). The four objects highlighted in Sect. 6.2 are labeled (a)–(d), as in Fig. 13.