4.4. Application to statistical samples

Perhaps the biggest challenge faced by these models is to make them tractable for application to statistical samples of galaxies, while at the same time retaining their fundamental predictive power. A first step in this direction was made by Misiriotis et al. [38] who applied the model of Popescu et al. [46] to further edge-on galaxies modelled in the optical by Xilouris et al. [Xilouris et al.1999]. More recently, Misiriotis et al. [40] used the same model, in simplified form, to fit the FIR SEDs of a submm selected sample of local universe spiral galaxies. As an example of what one can derive from such a study we show the derived star-formation rate surface density as a function of gas surface density (see Fig. 13).

Figure 13. Star-formation rate surface density predicted from the SED modelling (solid circles) of a submm selected sample and from the H measurements (open circles) of a sample of normal galaxies, as a function of gas surface density (Misiriotis et al. [40]). The dotted, dashed and dot-dashed lines correspond to star formation efficiencies of 100%, 10% and 1% in 108 yr.