| Description |
We propose Herschel observations of a complete sample of 3C radio-galaxies and quasars at redshift z<1. For all sources Spitzer mid-IR spectra are available. The aim is to quantify the orientation-dependence of AGN radiation (AGN unification), to investigate the interplay between accretion onto the central black-hole and star-formation in the hosts, and to understand the evolution of the black-hole/stellar-bulge relation. The low-frequency radio-selection provides us with powerful and massive active galaxies free from any orientation/obscuration bias, a requirement for testing AGN unification. The properties of the 3C sources are well known throughout the electromagnetic spectrum, except in the far-IR/sub-mm, where most of them were hitherto outside the capability of space missions to reach reliable measurements. We propose PACS 70-160 micron photometry of 72 sources supplemented by SPIRE 250-500 micron photometry of 11 sufficiently bright sources, in order to measure their detailed spectral energy distributions between available Spitzer and SCUBA/MAMBO data. Depending on redshift of the sources and predicted flux, the filter choice is optimised to provide best rest-frame FIR coverage. The rest-frame FIR emission serves as an isotropic calorimeter and the MIR/FIR luminosity ratio is determined by the relative strength of the AGN and star-forming contributions combined with dust obscuration. These observations will return crucial new information on the energy processes in powerful AGN and their hosts at z<1, providing an essential anchor for studies of galaxy and AGN evolution, in particular for a consistent comparison with Herschel observations of several (radio-loud) AGN samples at cosmic epochs z>1. |
