ner_tags: O O O O O O O O O O O O O O O O O O O O B-Wavelength O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B-Wavelength O O B-Wavelength O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B-Formula I-Formula I-Formula O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B-Wavelength O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B-Wavelength O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B-Formula I-Formula I-Formula I-Formula I-Formula O B-Formula I-Formula I-Formula I-Formula I-Formula O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O
tokens: the significant (and measurable) differences between the two models at the resolution of our spectrophotometric data, especially for the Mg UV and D4000 indices (marked in both plots as coloured areas). In Fig. 10 , we present the stacks built for the mature and senior galaxy populations together with the models characterized by their average properties. We also show the indices measured in the stacks of the mature, intermediate, and senior galaxy populations, and the tracks predicted by the model characterized by the average time-scales and dust attenuations quoted in Table 3 for each sub-population. The indices measured directly from the stacks are consistent with those predicted by the tracks of the models with the average properties of each sub-population. We demonstrate that the spectrophotometric data directly show the differences in the stellar population properties for the three sub-samples. Note that the origin of the average stellar population properties is the full SED spectral fits, and here we are comparing those models with finer resolution data in a limited wavelength range. The two analyses are not completely independent, but the information encoded in the data at the resolution which makes index measurements possible could easily be erased or degraded by fitting the whole SED from the UV to the mid-IR. Our test demonstrates that we are seeing differences in the galaxy populations in both the global SED and the spectral indices. We, thus, conclude that our results about the ages of MQGs at z = 1.0–1.5 are robust and not an artefact linked to the SED-fitting degeneracies. Figure 10. Left-hand panel: stacks for the senior (thick red line) and mature (thick blue line) populations normalized in the Mg UV (upper panel) and D4000 regions (lower panel). The average error of the stacks is ∼10 per cent. We used the dispersion as uncertainties (actual errors calculated by propagating the observed flux uncertainties were negligible). We also plot the normalized models with the average properties of each sub-population (thin red and blue lines). Right-hand panel: Mg UV versus D4000 plane, with the indices measured in the stacks for the mature, intermediate, and senior galaxies (blue, green, and red diamonds with error bars). For comparison, we also show the evolutionary tracks for two models with different star formation time-scales (an SSP and a delayed exponential model with τ = 1000 Myr) and two different dust attenuations ( A v = 0.0 mag and A v = 1.0 mag). The open circles represent the expected index values for each track at different ages (given in Gyr in the plot). The three coloured lines show the tracks predicted by the models with the average properties of each galaxy population (given in the legend). The filled coloured circles mark the indices values at different ages (0.5, 1.0, 2.0, 3.0, 5.0 Gyr, from smaller to larger symbols). The indices measured in the stacks are compatible with the average properties derived from the