Active Galactic Nuclei and their role in Galaxy Formation and Evolution

Summary We have presented the compelling new AGN science that can be accomplished with sub-mas resolution. In particular, such observations would enable us to constrain the energetics of the AGN “feedback” mechanism, which is critical for understanding the role of AGN in galaxy formation and evolution. These observations can only be obtained by long-baseline interferometers or sparse aperture telescopes in space, since the aperture diameters required are in excess of 500 m – a regime in which monolithic or segmented designs are not and will not be feasible and because these observations require the detection of faint emission near the bright unresolved continuum source, which is impossible from the ground, even with adaptive optics. Two mission concepts which could provide these invaluable observations are NASA’s Stellar Imager (SI; Carpenter et al. 2008 & http://hires.gsfc.nasa.gov/si/) interferometer and ESA’s Luciola (Labeyrie 2008) sparse aperture hypertelescope. For example, the small field-of-view of SI will permit us to observe close to the AGN while minimizing the scattered light from the central source. However, another possibility would be to include a nulling coronagraph instrument on either of these telescopes.