Triggering processes and star formation in AGN: multi-wavelength matters

AGN can be selected via an array of multi-wavelength diagnostics, spanning the X-ray and optical, to the mid-IR and radio.  Many studies of AGN and host galaxy properties focus on samples selected in only one of these domains. However, AGN selected at different wavelengths can exhibit very different properties, such that understanding the "big picture" requires a simultaneous multi-wavelength approach. In this talk, I will present a homogeneous analysis of 3 large samples of z~0 AGN, selected in the radio, mid-IR and optical in order to address the following two questions: what are the triggering mechanisms of AGN accretion, and what are the star formation rates of the host galaxies?  Thanks to the combination of multi-wavelength data, large samples, and homogeneous treatment, it is possible to distinguish different triggering mechanisms (e.g. mergers vs. secular) contributing to different AGN samples, and clearly measure differences in their relative star formation rates.