Active Galactic Nuclei and their role in Galaxy Formation and Evolution

TL;DR

This paper discusses the importance of high-resolution UV/optical observations of AGN's central regions to understand their role in galaxy formation, emphasizing the need for space-based interferometry with large apertures.

Contribution

It highlights the potential of space-based long-baseline interferometers to probe AGN feedback mechanisms and their impact on galaxy evolution.

Findings

High angular resolution observations can constrain AGN feedback energetics.

Space-based interferometers are necessary for faint emission detection near bright sources.

Proposed missions include NASA's Stellar Imager and ESA's Luciola hypertelescope.

Abstract

There are several key open questions as to the nature and origin of AGN including: 1) what initiates the active phase, 2) the duration of the active phase, and 3) the effect of the AGN on the host galaxy. Critical new insights to these can be achieved by probing the central regions of AGN with sub-mas angular resolution at UV/optical wavelengths. 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.