On Nulling Interferometers and the Line-emitting Regions of Active Galactic Nuclei

摘要

The nulling interferometers proposed to study planets around other stars are generally well suited for studying small-scale structures surrounding other bright pointlike objects, such as the nuclei of active galaxies. Conventional interferometric techniques will produce useful maps of optical /IR line and continuum emission in active galaxies on scales of 10 mas, but similar studies of broad- line regions will require baselines longer than those currently envisaged. Nevertheless, nulling interferometers currently under development will be able to constrain quasar velocity fields on 1 mas scales, as long as they are equipped with spectrographs capable of resolving lines several hundred km s~-1 wide.