The significance of AGN-induced outflows in nearby radio galaxies

In the light of the speculation that AGN-induced outflows have a significant effect on the evolution of bulge-dominated galaxies, I review the evidence for such outflows based on observations of radio-loud AGN in the local universe. On the large (5–500 kpc) scale, the radio jets drive massive outflows that clearly have a major impact on the energetics of the IGM. However, although there is also clear evidence for outflows in the warm and cool gas on the smaller scale (<5 kpc) of galaxy bulges, these outflows are much less energetic than required by the galaxy evolution models, even in cases in which the central black hole is currently growing rapidly by merger-induced accretion. It is possible that most of the energy of the outflows is tied up in hotter or cooler phases of the ISM that are difficult to detect at optical wavelengths.