Angular differential kernel phases

Abstract

To reach its optimal performance, Fizeau interferometry requires that we work to resolve instrumental biases through calibration. One common technique used in high contrast imaging is angular differential imaging, which calibrates the point spread function and flux leakage using a rotation in the focal plane. Our aim is to experimentally demonstrate and validate the efficacy of an angular differential kernel-phase approach, a new method for self-calibrating interferometric observables that operates similarly to angular differential imaging, while retaining their statistical properties. We used linear algebra to construct new observables that evolve outside of the subspace spanned by static biases. On-sky observations of a binary star with the SCExAO instrument at the Subaru telescope were used to demonstrate the practicality of this technique. We used a classical approach on the same data to compare the effectiveness of this method. The proposed method shows smaller and more Gaussian residuals compared to classical calibration methods, while retaining compatibility with the statistical tools available. We also provide a measurement of the stability of the SCExAO instrument that is relevant to the application of the technique. Angular differential kernel phases provide a reliable method for calibrating biased observables. Although the sensitivity at small separations is reduced for small field rotations, the calibration is effectively improved and the number of subjective choices is reduced.

To be published in Astronomy & Astrophysics, 11 pages, 7 figures

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Cited by in corpus (5)

• The Near Infrared Imager and Slitless Spectrograph for the James Webb Space Telescope -- IV. Aperture Masking Interferometry
• The Near Infrared Imager and Slitless Spectrograph for JWST -- V. Kernel Phase Imaging and Data Analysis
• Kernel Phase and Coronagraphy with Automatic Differentiation
• Mid-infrared photometry of the T Tauri triple system with kernel phase interferometry
• Searching for Protoplanets around MWC 758 and MWC 480 in Br-$\gamma$ using Kernel Phase and SCExAO/CHARIS