Millimeter measurements of hard X-ray selected active galaxies: implications for the nature of the continuous spectrum

We report measurements of 11 hard X-ray selected active galaxies at 800 and 1100 μm made with the James Clerk Maxwell Telescope, and discuss these in the context of the continuum energy distribution from radio to X-ray wavelengths. Four other radio-loud AGN were also measured. Radio-loud objects show a spectrum which decreases smoothly in flux to higher frequencies, and supporting evidence strongly suggests a non-thermal origin. For radio-quiet objects we report only upper limits, but in all cases the fall from 100 μm to 1 mm is steep, strongly suggesting that thermal emission dominates the far-IR emission. (author)