2010/09/20 by Frantz Martinache · 104 citations
Mathematics · Physics and Astronomy · #Adaptive optics #Adaptive optics and wavefront sensing #Aperture (computer memory) #Astronomy and Astrophysical Research #Interferometry #Kernel (algebra) #Mathematics #Observable #Optics #Physics #Stellar, planetary, and galactic studies #Strehl ratio #astro-ph.IM
paper · pdf · doi:10.1088/0004-637x/724/1/464
published in The Astrophysical Journal 724(1), 464-469 (IOP Publishing) · 7 pages, 5 figures, accepted for publication in ApJ
arxiv created 2010/09/20 · openalex publication_date 2010/11/02 · arxiv updated 2015/05/20 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
The detection of high contrast companions at small angular separation appears feasible in conventional direct images using the self-calibration properties of interferometric observable quantities. The friendly notion of closure-phase, which is key to the recent observational successes of non-redundant aperture masking interferometry used with Adaptive Optics, appears to be one example of a wide family of observable quantities that are not contaminated by phase-noise. In the high-Strehl regime, soon to be available thanks to the coming generation of extreme Adaptive Optics systems on ground based telescopes, and already available from space, closure-phase like information can be extracted from any direct image, even taken with a redundant aperture. These new phase-noise immune observable quantities, called kernel-phases, are determined a-priori from the knowledge of the geometry of the pupil only. Re-analysis of archive data acquired with the Hubble Space Telescope NICMOS instrument, using this new kernel-phase algorithm demonstrates the power of the method as it clearly detects and locates with milli-arcsecond precision a known companion to a star at angular separation less than the diffraction limit.