Florentin Millour

Pushing the limiting magnitude of optical interferometry: a case study

Abstract: I will present two aspects of a research work ongoing to push forward the sensitivity of optical interferometers. Indeed, the first-generations of optical interferometers have provided deceiving sensitivity limits, restricting this technique mainly to bright stars. This limited in practice the science related to extragalactic objects, and especially AGNs, which were only observable in thermal infrared. The advent of spectro-interferometry, mainly with the workhorse instrument AMBER on the VLTI, led us to rethink the paradigm of what sets the sensitivity limits of an optical interferometer. I will present here the results of the AGN study conducted with the AMBER instrument in the past three years and how we managed to progress on that aspect thanks to a new observing strategy approach, and show some ideas being developped to enhance significantly the limiting magnitude of current and future interferometers.