Peaked-spectrum sources radio and optical data

We compute the radio source counts of our PS sample, and find they are scaled down by a factor of 40 compared to a general sample of radio-loud active galactic nuclei (AGN). This implies that the lifetimes of PS sources are 40 times shorter than large scale radio galaxies, if their luminosity functions are identical. To investigate this, we compute the first radio luminosity function for a homogeneously-selected PS sample.

We find that for 144MHz luminosities >=10^25^W/Hz, the PS luminosity function has the same shape as an unresolved radio-loud AGN population but shifted down by a factor of 10.We interpret this as strong evidence that these high-luminosity PS sources evolve into large-scale radio-loud AGN. For local, low-luminosity PS sources, there is a surplus of PS sources, which we hypothesise to be the addition of frustrated PS sources that do not evolve into large-scale AGN.