Kernel-phase analysis: aperture modeling prescriptions that minimize calibration errors

Abstract

Kernel-phase is a data analysis method based on a generalization of the notion of closure-phase invented in the context of interferometry, but that applies to well corrected diffraction dominated images produced by an arbitrary aperture. The linear model upon which it relies theoretically leads to the formation of observable quantities robust against residual aberrations. In practice, detection limits reported thus far seem to be dominated by systematic errors induced by calibration biases not sufficiently filtered out by the kernel projection operator. This paper focuses on the impact the initial modeling of the aperture has on these errors and introduces a strategy to mitigate them, using a more accurate aperture transmission model. The paper first uses idealized monochromatic simulations of a non trivial aperture to illustrate the impact modeling choices have on calibration errors. It then applies the outlined prescription to two distinct data-sets of images whose analysis has previously been published. The use of a transmission model to describe the aperture results in a significant improvement over the previous type of analysis. The thus reprocessed data-sets generally lead to more accurate results, less affected by systematic errors. As kernel-phase observing programs are becoming more ambitious, accuracy in the aperture description is becoming paramount to avoid situations where contrast detection limits are dominated by systematic errors. Prescriptions outlined in this paper will benefit any attempt at exploiting kernel-phase for high-contrast detection.

arXiv comment12 pages, 15 figures, accepted for publication by Astronomy & Astrophysics

References in corpus (15)

• The Subaru Coronagraphic Extreme Adaptive Optics system: enabling high-contrast imaging on solar-system scales
• LkCa 15: A Young Exoplanet Caught at Formation?
• Mapping the Shores of the Brown Dwarf Desert I.: Upper Scorpius
• PALM-3000: Exoplanet Adaptive Optics for the 5-meter Hale Telescope
• Fast computation of Lyot-style coronagraph propagation
• Kernel-Phase in Fizeau Inteferometry
• Phase Errors in Diffraction-Limited Imaging: Contrast Limits for Sparse Aperture Masking
• The Asymmetric Pupil Fourier Wavefront Sensor
• Comparing Non-Redundant Masking and Filled-Aperture Kernel Phase for Exoplanet Detection and Characterization
• Establishing Alpha Oph as a Prototype Rotator: Improved Astrometric Orbit
• Visual orbit of GJ 164 AB
• Kernel phase imaging with VLT/NACO: high-contrast detection of new candidate low-mass stellar companions at the diffraction limit
• Phase-Induced Amplitude Apodization on centrally obscured pupils: design and first laboratory demonstration for the Subaru Telescope pupil
• Kernel-phase Detection Limits : Hypothesis Testing and the Example of JWST NIRISS Full Pupil Images
• Recovering saturated images for high dynamic Kernel-Phase analysis Application to the determination of dynamical masses for the system Gl 494AB

Cited by in corpus (8)

• 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
• A Geometric View of Closure Phases in Interferometry
• NICMOS Kernel-Phase Interferometry I: Catalogue of Brown Dwarfs Observed in F110W and F170M
• Mid-infrared photometry of the T Tauri triple system with kernel phase interferometry
• High-contrast detection of exoplanets with a kernel-nuller at the VLTI
• Searching for Protoplanets around MWC 758 and MWC 480 in Br-$\gamma$ using Kernel Phase and SCExAO/CHARIS