Constraining the gas distribution in the PDS 70 disk as a method to assess the effect of planet-disk interactions

Abstract

Embedded planets are potentially the cause of substructures like gaps and cavities observed in several protoplanetary disks. Thus, the substructures observed in the continuum and in line emission encode information about the presence of planets in the system and how they interact with the natal disk. The pre-transitional disk around the star PDS 70 is the first case of two young planets imaged within a dust depleted gap that was likely carved by themselves. We aim to determine the spatial distribution of the gas and dust components in the PDS 70 disk. The axisymmetric substructures observed in the resulting profiles are interpreted in the context of planet-disk interactions. We develop a thermo-chemical forward model for an axisymmetric disk to explain a subset of the Atacama Large Millimeter/Submillimeter Array (ALMA) band 6 observations of three CO isotopologues plus the continuum towards PDS 70. Combining the inferred gas and dust distributions, the model results in a variable gas-to-dust ratio profile throughout the disk that spans two orders of magnitude within the first $130$ au and shows a step gradient towards the outer disk, which is consistent with the presence of a pressure maxima driven by planet-disk interactions. We find a gas density drop factor of $\sim 19$ at the location of the planet PDS 70 c with respect to the peak gas density at $75$ au. Combining this value with literature results on the hydrodynamics of planet-disk interactions, we find this gas gap depth to be consistent with independent planet mass estimates from infrared observations. Our findings point towards gas stirring processes taking place in the common gap due to the gravitational perturbation of both planets.

Accepted for publication in A&A

References in corpus (17)

• Two accreting protoplanets around the young star PDS 70
• Dust filtration at gap edges: Implications for the spectral energy distributions of discs with embedded planets
• Radiative transfer in very optically thick circumstellar disks
• Mass Estimates of a Giant Planet in a Protoplanetary Disk from the Gap Structures
• Hydrocarbon emission rings in protoplanetary disks induced by dust evolution
• Submillimeter emission associated with candidate protoplanets
• Highly structured disk around the planet host PDS 70 revealed by high-angular resolution observations with ALMA
• Constraining the Nature of the PDS 70 Protoplanets with VLTI/GRAVITY
• Empirical constraints on turbulence in proto-planetary discs
• Consistent dust and gas models for protoplanetary disks: II. Chemical networks and rates
• Keck/NIRC2 $L$'-Band Imaging of Jovian-Mass Accreting Protoplanets around PDS 70
• VLT/SPHERE exploration of the young multiplanetary system PDS70
• The chemical inventory of the planet-hosting disk PDS 70
• The widest H$\alpha$ survey of accreting protoplanets around nearby transition disks
• Shallow Cavities in Multiple-Planet Systems
• Gas temperature structure across transition disk cavities
• Kinematics and brightness temperatures of transition discs -- A survey of gas substructures as seen with ALMA

Cited by in corpus (9)

• Water in the terrestrial planet-forming zone of the PDS 70 disk
• MINDS: JWST/NIRCam imaging of the protoplanetary disk PDS 70
• Dust mineralogy and variability of the inner PDS 70 disk
• ALMA high-resolution observations unveil planet formation shaping molecular emission in the PDS 70 disk
• Constraints on PDS 70 b and c from the dust continuum emission of the circumplanetary discs considering in situ dust evolution
• On the suppression of giant planet formation around low-mass stars in clustered environments
• Differentiating Formation Models with New Dynamical Masses for the PDS 70 Protoplanets
• Radial variations in nitrogen, carbon, and hydrogen fractionation in the PDS 70 planet-hosting disk
• Semianalytical Accretion-Tracer Emission: Forming Planets Are Intrinsically Faint