Category Archives: JWST

KERNEL Publication: Statistical Tests for high-contrast detection using KERNEL-PHASE!

In this new publication, KERNEL team PhD student Alban Ceau and collaborators formulate new formal tools and techniques to determine the contrast detection limits for a planned JWST program designed to look for companions around ultracool Y-dwarfs.

The paper notably introduces an operational test that turns out to be only marginally less powerful than the theoretical optimal (aka Neyman-Pearson) test. The operational test, applied to simulated JWST images of the NIRISS instrument expected to be representative of planned observations of faint Y-dwarfs suggests that companions of less than 1 Jupiter mass are well within the grasp of this observing mode.

Parameter estimation by the kernel-phase method for 10:1 contrast companions located inside or outside lambda/D (~ 150 mas at the wavelength of the simulation). For super-resolved detections, the contrast ratio and the angular separation are strongly correlated: a behavior that is similar to what has been observed for closure-phase when using a non-redundant aperture mask. Beyond one resolution element, the interpretation of the data is unequivocal.

Congratulations to Alban whose paper was accepted for publication by Astronomy & Astrophysics! The preprint version of the paper is available for download on the website: