Follow-up of the 9C survey: initial results

We present initial results from a follow-up of the 9C survey, complete to 25 mJy at 15 GHz, designed to assemble and investigate a sample of young radio sources. We have made radio continuum maps of 111 sources at frequencies spanning 1.4–43 GHz, and classified them according to their radio size and spectral index between 1.4 and 4.8 GHz. We find that selection at 15 GHz is twice as efficient at picking Gigahertz Peaked Spectrum (GPS) sources as selection at ∼5 GHz. Optical follow-up has now begun; imaging of GPS and compact steep spectrum sources suggests that a significant fraction of the host galaxies have close companions or disturbed morphologies.