Offline, multidetector intensity interferometers – II. Implications and applications

Intensity interferometry removes the stringent requirements on mechanical precision and atmospheric corrections that plague all amplitude interferometry techniques at the cost of severely limited sensitivity. A new idea we recently introduced, very high redundancy, alleviates this problem. It enables the relatively simple construction (～1 cm mechanical precision) of a ground-based astronomical facility able to transform a two-dimensional field of point-like sources to a three-dimensional distribution of microarcsec resolved systems, each imaged in several optical bands. Each system will also have its high-resolution residual timing, high-quality (inside each band) spectra and light curve, emergent flux, effective temperature, polarization effects and perhaps some thermodynamic properties, all directly measured. All the above attributes can be measured in a single observation run of such a dedicated facility. We conclude that after three decades of abandonment, optical intensity interferometry deserves another review, also as a ground-based alternative to the science goals of space interferometers.