2009/02/16 by A. Chelli, G. Duvert, F. Malbet +1
Physics and Astronomy · #Astronomy and Astrophysical Research #Astrophysics and Star Formation Studies #Stellar, planetary, and galactic studies #astro-ph.IM #astro-ph.SR
paper · pdf · doi:10.1051/0004-6361/200811036
arxiv created 2009/02/16 · openalex publication_date 2009/02/18 · arxiv updated 2009/12/01 · openalex created_date 2020/11/23 · openalex updated_date 2026/07/11
We provide a complete theory of the phase closure of a binary system in which a small, feeble, and unresolved companion acts as a perturbing parameter on the spatial frequency spectrum of a dominant, bright, resolved source. We demonstrate that the influence of the companion can be measured with precision by measuring the phase closure of the system near the nulls of the primary visibility function. In these regions of <i>phase closure nulling<i/>, frequency intervals always exist where the phase closure signature of the companion <i>is larger than any systematic error<i/> and can then be measured. We show that this technique allows retrieval of many astrophysically relevant properties of faint and close companions such as flux, position, and in favorable cases, spectrum. We conclude by a rapid study of the potentialities of phase closure nulling observations with current interferometers and explore the requirements for a new type of dedicated instrument.