AGN feedback drives the colour evolution of local galaxies
  We investigate the effects of AGN feedback on the colour evolution of
galaxies found in local (z<0.2) groups and clusters. Galaxies located within
the lobes of powerful Fanaroff-Riley type II (edge-brightened) sources show
much redder colours than neighbouring galaxies that are not spatially
coincident with the radio source. By contrast, no similar effect is seen near
Fanaroff-Riley type I (core-dominated) radio sources. We show that these
colours are consistent with FR-IIs truncating star formation as the expanding
bow shock overruns a galaxy. We examine a sample of clusters with no detectable
radio emission and show that galaxy colours in these clusters carry an imprint
of past AGN feedback. AGN activity in the low-redshift Universe is
predominantly driven by low-luminosity radio sources with short duty cycles.
Our results show that, despite their rarity, feedback from powerful radio
sources is an important driver of galaxy evolution even in the local volume.
