Figure 2

Figure 2.  Galaxy SED as a function of age. A is a Bruzual-Charlot model at t=3 ´ 106 years (metallicity 0.004 solar, single burst) with no dust extinction and therefore no far-infrared flux (Bruzual & Charlot, 1993). B shows the same model at t=1 ´ 107 years with Av=1 and far-infrared flux scaled to equal the energy absorbed at short wavelengths. The Calzetti extinction law has been used (Calzetti et al. 1994).   C is the same as B, but for t=5 ´ 107 years. D is the same for B, but for t=1.3 ´ 10 8 years. Flux scale is arbitrary. From M. Rieke (private communication).