Resulting spectrum from the stacking analysis of star forming galaxies. The blue line shows the continuum subtracted data, while the red dashed line indicates the best fit to the stacked spectrum. Top row: Stacked spectrum of Hα, [N II] and [S II] (left panel) and He IIλ4686, Hβ and [O III] λ5008 (right panel). Bottom row: Stacked spectrum of C IV (left panel), He IIλ1640 and [O III] λ1666 (middle panel), and C III] (right panel).