Complete Sample of Northern Hemisphere Active Galactic Nuclei-Differences in Fluxand Spectra at High Radio Frequencies

摘要

The authors present two-epoch 22 and 37 GHz flux measurements of a complete 1 Jysample of flat-spectrum extragalactic radio sources. The spectral and variability properties of quasars and blazars in the sample are similar. Radio galaxies, which have steeper cm-to-mm spectra, are the only sources which can be identified solely on the basis of their radio continuum properties. Surprisingly, among the flat-spectrum sources the BL Lacs and low polarization quasars with the steepest spectra seem to be the most variable ones. The implications of these results for orientation-dependent unified models for active galaxies are discussed.