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Apr 28
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Sam Factor
The University of Texas at Austin
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Kernel-Phase Interferometry for Super-Resolution Detection of Faint Companions (2nd Year Defense)
Direct detection of close in companions (exoplanets or binary systems) is notoriously difficult. While coronagraphs and point spread function (PSF) subtraction can be used to reduce contrast and dig out signals of companions under the PSF, these methods work best at >>lambda/D, so there are still significant limitations in separation and contrast. Non-redundant aperture masking (NRM) interferometry can be used to detect companions even inside lambda/D of a diffraction limited image, though the mask discards ~95% of the light gathered by the telescope and thus the technique is severely flux limited. Kernel-phase analysis applies interferometric techniques similar to NRM to a diffraction limited image utilizing the full aperture. Instead of non-redundant closure-phases, kernel-phases are constructed from a grid of points on the full aperture, simulating a redundant interferometer. I have developed a new, user-friendly, faint companion detection pipeline which analyzes kernel-phases utilizing Bayesian model comparison. I am working to demonstrate this pipeline on archival images from NICMOS/NIC1 in order to search for new companions and constrain binary formation models at separations inaccessible to previous techniques. Using this method, it is possible to detect a companion well within the classical lambda/D Rayleigh diffraction limit using a fraction of the telescope time as NRM. This technique can easily be applied to archival data, as no mask is needed, and will thus make the detection of close in companions cheap and simple. Since the James Webb Space Telescope (JWST) will be able to perform both NRM and kernel-phase observations, further development and characterization of kernel-phase analysis will allow efficient use of highly competitive JWST telescope time.
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