High resolution imaging with Fresnel interferometric arrays: suitability for exoplanet detection

¹ Observatoire Midi Pyrénées, 14 avenue Edouard Belin, 31400 Toulouse, France
² Centre National d'études spatiales, 18 avenue Edouard Belin, 31055 Toulouse Cedex, France

Received: 15 February 2005
Accepted: 20 July 2005

Abstract

We propose a new kind of interferometric array that yields images of high dynamic range and large field. The numerous individual apertures in this array form a pattern related to a Fresnel zone plate. This array can be used for astrophysical imaging over a broad spectral bandwidth spanning from the UV (50 nanometers) to the IR (20 μm). Due to the long focal lengths involved, this instrument requires formation-flying of two space borne vessels. We present the concept and study the S/N ratio in different situations, then apply these results to probe the suitability of this concept to detect exoplanets.