AR 16612 (Archival Research)

Sun Jul 14 04:52:25 GMT 2024

Principal Investigator: Samuel Factor
PI Institution: University of Texas at Austin
Investigators (xml)

Title: Discovery of Young Planetary Systems with Kernel-Phase Interferometry
Cycle: 29

Filling the gap between directly-imaged and RV/transiting planets will test theories of planet formation across the full range of semi-major axes, connecting formation of close to wide separation gas giants and substellar companions. Companions are notoriously hard to image near lambda/D, as coronagraphs and PSF subtraction techniques are best at >>lambda/D. Non-redundant aperture masking interferometry (NRM) can reveal companions at relevant scales, but is severely flux-limited due to the mask. Kernel-phase interferometry (KPI) applies a similar analysis to (archival) unobscured images, treating the full aperture as a grid of interfering subapertures. We have completed a new KPI pipeline for HST/NICMOS and demonstrated it for a binary survey of nearby old brown dwarfs, refining the astrometry of known companions and clarifying past marginal detections. We have also characterized the detection limits, demonstrating significant sensitivity down to flux ratios of ~10^2 at 0.5 lambda/D. If applied to HST imaging of young brown dwarfs, KPI reaches planetary-masses (~3-5 MJup) on Solar-System scales (>6 AU). We therefore propose a KPI search for planetary mass companions (PMCs) in HST/ACS imaging of 34 young BDs and low-mass stars in the young star-forming regions of Taurus and Upper Scorpius. Past (classical) image analysis was only sensitive to wide (>50 au) PMCs, but we will find companions down to ~5 au, an orbital range where young PMCs (e.g. 2M1207b) have been discovered with more classical techniques around the very nearest young BDs. We will also discover 3-5 new binary companions at tight separations which test models of binary formation and young BD evolution.