Patru, F.F.PatruESPOSITO, SimoneSimoneESPOSITOPUGLISI, Alfio TimothyAlfio TimothyPUGLISIRICCARDI, ArmandoArmandoRICCARDIPINNA, EnricoEnricoPINNAARCIDIACONO, CARMELOCARMELOARCIDIACONOAntichi, J.J.AntichiMennesson, B.B.MennessonDefrère, D.D.DefrèreHinz, P. M.P. M.HinzHill, J. M.J. M.Hill2021-01-212021-01-2120170035-8711http://hdl.handle.net/20.500.12386/29907We show by numerical simulations a fundamental gain in contrast when combining coherently monochromatic light from two adaptive optics (AO) telescopes instead of using a single stand-alone AO telescope, assuming efficient control and acquisition systems at high speed. A contrast gain map is defined as the normalized point spread functions (PSFs) ratio of a single Large Binocular Telescope (LBT) aperture over the dual Large Binocular Telescope Interferometer (LBTI) aperture in Fizeau mode. The global gain averaged across the AO-corrected field of view is improved by a factor of 2 in contrast in long exposures and by a factor of 10 in contrast in short exposures (i.e. in exposures, respectively, longer or shorter than the coherence time). The fringed speckle halo in short exposures contains not only high-angular resolution information, as stated by speckle imaging and speckle interferometry, but also high-contrast imaging information. A high-gain zone is further produced in the valleys of the PSF formed by the dark Airy rings and/or the dark fringes. Earth rotation allows us to exploit various areas in the contrast gain map. A huge-contrast gain in narrow zones can be achieved when both a dark fringe and a dark ring overlap on to an exoplanet. Compared to a single 8-m LBT aperture, the 23-m LBTI Fizeau imager can provide a gain in sensitivity (by a factor of 4), a gain in angular resolution (by a factor of 3) and, as well, a gain in raw contrast (by a factor of 2-1000 varying over the AO-corrected field of view).STAMPAenArticle10.1093/mnras/stx19612-s2.0-85030569360000413088400004https://academic.oup.com/mnras/article/472/3/2544/40621992017MNRAS.472.2544PFIS/05 - ASTRONOMIA E ASTROFISICAERC sectors::Physical Sciences and Engineering::PE9 Universe sciences: astro-physics/chemistry/biology; solar systems; stellar, galactic and extragalactic astronomy, planetary systems, cosmology, space science, instrumentation::PE9_6 Stars and stellar systems