Spectral differential imaging using kernel phase with CHARIS/SCExAO: technique performance and current limitation

Kernel phase interferometry (KPI) is a data processing technique that allows for the detection of asymmetries arising from companions or disks in high-Strehl AO-corrected images, close to or beyond the limit of traditional approaches. We show that this technique can be applied to the CHARIS IFS (with SCExAO), by recovering a known binary HD 44927 with CHARIS's high resolution K-band mode. Currently, KPI is limited by residual systematic errors in the kernel phases. We show that these errors can be mitigated during calibration, by taking advantage of the information available in adjacent wavelength bands. This spectral differential imaging (SDI) calibration method is a promising avenue towards achieving photon noise limited kernel phase observations.