2008A&A...488L..59L

I study the interaction between young AGN and their host galaxies based on their ionized gas and radio emission, and analyze possible implications for radio galaxy evolution. The [OIII] λ 5007Å line and 5-GHz radio properties are compared and studied for a large, representative sample of GPS and CSS (i.e., young) quasars and radio galaxies, and large-scale sources using [OIII] λ 5007Å line and 5-GHz radio data from the literature and our own observations. Several correlations between the [OIII] λ 5007Å line and 5-GHz radio emission were found. The main result is that the [OIII] λ 5007Å emission is strongly correlated with the GPS/CSS source size, which indicates that the [OIII] λ 5007Å emission is enhanced significantly by the jet expansion through the host galaxy ISM. Shocks are the most likely enhancement mechanism, although jet-induced star formation could be also, partly, responsible for the [OIII] λ 5007Å emission. The data also suggests that the jet possibly decelerates as it grows, although the correlation expansion speed versus radio size is weak.