PDS 70 unveiled by star-hopping: total intensity, polarimetry and mm-imaging modeled in concert

Abstract

Context. Most ground-based planet search direct imaging campaigns use angular differential imaging, which distorts the signal from extended sources like protoplanetary disks. In the case PDS 70, a young system with two planets found within the cavity of a protoplanetary disk, obtaining a reliable image of both planets and disk is essential to understanding planet-disk interactions. Aims. Our goals are to reveal the true intensity of the planets and disk without self-subtraction effects for the first time, search for new giant planets beyond separations of 0.1" and to study the morphology of the disk shaped by two massive planets. Methods. We present YJHK-band imaging, polarimetry, and spatially resolved spectroscopy of PDS 70 using near-simultaneous reference star differential imaging, also known as star-hopping. We created a radiative transfer model of the system to match the near-infrared imaging and polarimetric data, along with sub-millimeter imaging from ALMA. Furthermore, we extracted the spectra of the planets and the disk and compared them. Results. We find that the disk is quite flared with a scale height of ~15% at the outer edge of the disk at ~90 au, similar to some disks in the literature. The gap inside of ~50 au is estimated to have ~1% of the dust density of the outer disk. The Northeast outer disk arc seen in previous observations is likely the outer lip of the flared disk. Abundance ratios of grains estimated by the modeling indicate a shallow grain-size index > -2.7, instead of the canonical -3.5. There is both vertical and radial segregation of grains. Planet c is well separated from the disk and has a spectrum similar to planet b, clearly redder than the disk spectra. Planet c is possibly associated with the sudden flaring of the disk starting at ~50 au. No new planets > 5 Mj were found.

Accepted to A&A on April 11, 2024. 20 pages, 19 figures

References in corpus (18)

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• Fundamental limitations of high contrast imaging set by small sample statistics
• A Circumplanetary Disk Around PDS70c
• Submillimeter emission associated with candidate protoplanets
• Constraining the Nature of the PDS 70 Protoplanets with VLTI/GRAVITY
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• The chemical inventory of the planet-hosting disk PDS 70
• A search for a 5th planet around HR 8799 using the star-hopping RDI technique at VLT/SPHERE
• Host star metallicity of directly imaged wide-orbit planets: implications for planet formation
• Protoplanetary disks in $K_s$-band total intensity and polarized light
• Analysis of the arm-like structure in the outer disk of PDS 70. Spiral density wave or vortex?
• Planet formation in the PDS 70 system: Constraining the atmospheric chemistry of PDS 70b and c
• HST UV Spectroscopy of the Planet-Hosting T Tauri Star PDS 70

Cited by in corpus (5)

• WIde Separation Planets In Time (WISPIT): A Gap-clearing Planet in a Multi-ringed Disk around the Young Solar-type Star WISPIT 2
• Differentiating Formation Models with New Dynamical Masses for the PDS 70 Protoplanets
• Keplerian motion of a compact source orbiting the inner disc of PDS 70: a third protoplanet in resonance with b and c?
• Occurrence rates of accreting companions from a new method for computing emission-line survey sensitivity: application to the H-alpha Giant Accreting Protoplanet Survey
• Modelling shadows in scattered light observations as signals from companions in protoplanetary discs