SEDs of the 8 GS galaxies. The solid red line shows the combination of the model fit of the (i) optical-NIR side of the SEDs done with the FAST code, (ii) IR energy distribution from the best-fitting Draine & Li (2007) model (gray dashed line), and when necessary (iii) the warm dust continuum heated by an AGN using the Mullaney et al. (2011) code “decompIR” (purple dashed line). The specific case of GS8, for which the optical counterpart is nearly undetected, is discussed in Sect. 3.1.