Extended Data Fig. 4: NUV and optical line-strength indices.
From: Sub one per cent mass fractions of young stars in red massive galaxies
The panels show the behaviour of the NUV and optical SSP model indices as a function of age, for two different metallicities ([M/H]=0.0, solid lines; [M/H]=+0.22, dashed lines). The black dots correspond to the observed measurements of BOSS stacked spectra and their error bars show the 1𝜎 uncertainty on the measurements. Red stars indicate the best fitting 2SSPs model predictions. Blue triangles show the index values predicted by the best fitting 1SSP+cSFR model. Note that the discrepancy between SSP model predictions and data increases towards bluer indices. The indices shown exclude those in Figure 1.
