Parameter dependencies between old/young population age, mass fraction, dust A_V and stellar mass for LAE_COSMOS_154 (left) and LAE_COSMOS_37 (right). Contours mark 68%, 95% and 99.7% probability. The green point marks the χ²-weighted best fit parameter, with the 1σ error bar as found in Table 6. For the object in the left panels, the stellar mass is well constrained. The mass fraction in the young population is low, and hence the older population age is also well constrained. In this case, the younger population has a larger span of possible solutions, partially dependent on the A_V. This is an example of a galaxy for which the older population age is observed, as opposed to the object on the right. Here, the stellar mass and A_V are well constrained, but the young population age is very young, and the mass fraction in the young population is allowed to be any value above  ~50%. Hence, the older population age is completely unconstrained.