Broad-line radio galaxies: Old and feeble?

Far-infrared photometry of broad-line radio galaxies shows this class of AG N to consist of many hot and some cool infrared emitters, with peaks in the ir spectral energy distributions around 25 mum or longward of 60 mum, respe ctively. Quantitative analysis indicates that this distribution relates to a substantial dispersion in the strength of the cool dust component: broad- line radio galaxies are relatively poor in large-scale dust. Possibly they have undergone a different merger evolution, or are relatively old AGN.