Spectral energy distributions galaxies with m(3.4 μm)−m(4.6 μm) ≥ 2 mag. Observed SDSS optical spectra are shown by black solid lines; observed GALEX, SDSS and WISE monochromatic fluxes are shown by filled red circles. The WISE data are connected by a red solid line. The modelled SED shown by the blue line is a sum of stellar emission (green line) and ionised gas emission (magenta line).