Rawlings & Willott (2004) (GRW04):

$$\rm{log L([OIII]\lambda5007}) = 7.53 + 1.045\rm{log L(151~MHz).}$$

Eqn. (6) applies to the population as a whole, but following GRW04 we assume that the quasars and radio galaxies lie 0.3 dex systemtically above and below it, respectively, with an additional 0.5 dex of scatter on each distribution. To assign an AGN component to the infrared SED, we draw upon the findings of Haas et al. (2008) who presented [*Spitzer*]{} 3–24 photometry of 3CR steep-spectrum quasars and radio galaxies at redshift $1<z<2.5$. The quasar mid-infrared SEDs are very uniform, roughly constant in $\nu F_{\rm{\nu}}$. There is a near proportionality between $\nu F_{\rm{\nu}}$(8 , rest) and $\nu F_{\rm{\nu}}$(178 MHz, rest) with 0.5 dex scatter. The radio galaxies are dominated by host galaxy starlight below 3 (rest) and at longer wavelengths by a quasar nucleus reddened by up to A$_{\rm{V}}=50$ mag. The radio galaxies are a factor 3–10 less luminous in this spectral range than the quasars, which they attribute entirely to extinction. For a sample of 3CR sources at $0.4 \leq z <1.2$, Cleary et al. (2007) find that the quasars are 4 times as luminous as the radio galaxies at 15, half of which they attribute to 