Clustering, host galaxies, and evolution of AGN
  We explore the connection between different classes of active galactic nuclei
(AGNs) and the evolution of their host galaxies, by deriving host galaxy
properties, clustering, and Eddington ratios of AGNs selected in the radio,
X-ray, and infrared (IR) wavebands from the wide-field (9 deg^2) Bootes survey.
We study a sample of 585 AGNs at 0.25 < z < 0.8 using redshifts from the AGN
and Galaxy Evolution Survey (AGES). We find that radio and X-ray AGNs reside in
relatively large dark matter halos (M_halo ~ 3x10^13 and 10^13 h^-1 M_sun,
respectively) and are found in galaxies with red and "green" colors. In
contrast, IR AGNs are in less luminous galaxies, have higher Eddington ratios,
and reside in halos with M_halo < 10^12 M_sun. We interpret these results in
terms of a general picture for AGNs and galaxy evolution, in which quasar
activity is triggered when M_halo ~ 10^12 - 10^13 M_sun, after which star
formation ceases and AGN accretion shifts to optically-faint, X-ray and
radio-bright modes.
