A Multi-wavelength Survey of AGN in Massive Clusters: AGN Distribution
  and Host Galaxy Properties
  We investigate the effect of environment on the presence and fuelling of
Active Galactic Nuclei (AGN) by identifying galaxies hosting AGN in massive
galaxy clusters and the fields around them. We have identified AGN candidates
via optical variability (178), X-ray emission (74), and mid-IR SEDs (64) in
multi- wavelength surveys covering regions centered on 12 galaxy clusters at
redshifts 0.5 < z < 0.9. In this paper, we present the radial distribution of
AGN in clusters to examine how local environment affects the presence of an AGN
and its host galaxy. While distributions vary from cluster to cluster, we find
that the radial distribution of AGN generally differs from that of normal
galaxies. AGN host galaxies also show a different colour distribution than
normal galaxies, with many AGN hosts displaying galaxy colours in the "green
valley" between the red sequence and blue star-forming normal galaxies. This
result is similar to those found in field galaxy studies. The colour
distribution of AGN hosts is more pronounced in disturbed clusters where minor
mergers, galaxy harassment, and interactions with cluster substructure may
continue to prompt star-formation in the hosts. However, we find no
relationship between host galaxy colour and cluster radius among AGN hosts.
This may indicate that processes related to the accreting supermassive black
hole have a greater impact on the star-forming properties of the host galaxy
than the intracluster medium and/or local galaxy environment.
