2001A&A...368..414V

In order to study the nature of the far-infrared emission observed in radio-loud active galaxies, we have obtained 1.2 mm observations with the IRAM 30m telescope for a sample of eight radio-loud active galaxies. In all objects we find that the 1.2 mm emission is dominated by non-thermal emission. An extrapolation of the non-thermal radio spectrum indicates that the contribution of synchrotron emission to the far-infrared is less than 10% in quasars, and negligible in the radio galaxies. The quasars in the sample show signs of relativistic beaming at millimeter wavelengths, and the quasar 3C 334 shows evidence for strong variability.