Radiative scale-height and shadows in protoplanetary disks

Abstract

Planets form in young circumstellar disks called protoplanetary disks. However, it is still difficult to catch planet formation in-situ. Nevertheless, from recent ALMA/SPHERE data, encouraging evidence of the direct and indirect presence of embedded planets has been identified in disks around young stars: co-moving point sources, gravitational perturbations, rings, cavities, and emission dips or shadows cast on disks. The interpretation of these observations needs a robust physical framework to deduce the complex disk geometry. In particular, protoplanetary disk models usually assume the gas pressure scale-height given by the ratio of the sound speed over the azimuthal velocity $H/r=c_s/v_{\mathrm{k}}$. By doing so, \textit{radiative} pressure fields are often ignored, which could lead to a misinterpretation of the real vertical structure of such disks. We follow the evolution of a gaseous disk with an embedded Jupiter mass planet through hydrodynamical simulations, computing the disk scale-height including radiative pressure, which was derived from a generalization of the stellar atmosphere theory. We focus on the vertical impact of the radiative pressure in the vicinity of circumplanetary disks, where temperatures can reach $\gtrsim 1000$ K for an accreting planet, and radiative forces can overcome gravitational forces from the planet. The radiation-pressure effects create a vertical optically thick column of gas and dust at the proto-planet location, casting a shadow in scattered light. This mechanism could explain the peculiar illumination patterns observed in some disks around young stars such as HD 169142 where a moving shadow has been detected, or the extremely high aspect-ratio $H/r\sim 0.2$ observed in systems like AB Aur and CT Cha.

12 pages, 7 figures. Accepted for publication by ApJ

References in corpus (43)

• First Results from High Angular Resolution ALMA Observations Toward the HL Tau Region
• The Disk Substructures at High Angular Resolution Project (DSHARP): I. Motivation, Sample, Calibration, and Overview
• Passive irradiated circumstellar disks with an inner hole
• Discovery of a planetary-mass companion within the gap of the transition disk around PDS 70
• Particle Stirring in Turbulent Gas Disks: Including Orbital Oscillations
• ISO spectroscopy of circumstellar dust in 14 Herbig Ae/Be systems: towards an understanding of dust processing
• Rosseland and Planck Mean Opacities for Protoplanetary Discs
• Gaps and Rings in an ALMA Survey of Disks in the Taurus Star-forming Region
• The Disk Substructures at High Angular Resolution Project (DSHARP): II. Characteristics of Annular Substructures
• Spectral and Photometric Diagnostics of Giant Planet Formation Scenarios
• Characterization of exoplanets from their formation I: Models of combined planet formation and evolution
• The inner regions of protoplanetary disks
• Orbital and atmospheric characterization of the planet within the gap of the PDS 70 transition disk
• Shadows cast by a warp in the HD 142527 protoplanetary disk
• Structures in the protoplanetary disk of HD142527 seen in polarized scattered light
• Shadows cast on the transition disk of HD 135344B. Multiwavelength VLT/SPHERE polarimetric differential imaging
• Kinematic detection of a planet carving a gap in a protoplanetary disc
• Circumbinary, not transitional: On the spiral arms, cavity, shadows, fast radial flows, streamers and horseshoe in the HD142527 disc
• The Disk Substructures at High Angular Resolution Project (DSHARP): III. Spiral Structures in the Millimeter Continuum of the Elias 27, IM Lup, and WaOph 6 Disks
• Highly structured disk around the planet host PDS 70 revealed by high-angular resolution observations with ALMA
• Nine localised deviations from Keplerian rotation in the DSHARP circumstellar disks: Kinematic evidence for protoplanets carving the gaps
• Type I planetary migration in a self-gravitating disk
• Gaps in the HD169142 protoplanetary disk revealed by polarimetric imaging: Signs of ongoing planet formation?
• The co-orbital corotation torque in a viscous disk: numerical simulations
• Treating gravity in thin disk simulations
• Accretion kinematics through the warped transition disk in HD142527 from resolved CO(6-5) observations
• Signatures of broken protoplanetary discs in scattered light and in sub-millimetre observations
• A compact concentration of large grains in the HD142527 protoplanetary dust trap
• Chasing Shadows: Rotation of the Azimuthal Asymmetry in the TW Hya Disk
• Spiral waves triggered by shadows in transition disks
• Evidence for a circumplanetary disk around protoplanet PDS 70 b
• Variable dynamics in the inner disk of HD 135344B revealed with multi-epoch scattered light imaging
• Shadows and cavities in protoplanetary disks: HD163296, HD141569A, and HD150193A in polarized light
• Scattered light shadows in warped protoplanetary discs
• Differences in the gas and dust distribution in the transitional disk of a sun-like young star, PDS 70
• HD 169142 in the eyes of ZIMPOL/SPHERE
• Sculpting the disk around T Cha: an interferometric view
• Planetary-like spirals caused by moving shadows in transition discs
• Protoplanetary disks including radiative feedback from accreting planets
• Dusty spirals triggered by shadows in transition discs
• The growth of supermassive black holes fed by accretion disks
• Constraints on the height of the inner disk rim in pre-main-sequence stars
• Feedback-limited Accretion: Variable Luminosity from Growing Planets

Cited by in corpus (8)

• Investigating the Relative Gas and Small Dust Grain Surface Heights in Protoplanetary Disks
• Measurement of the angular momenta of pre-main-sequence stars: early evolution of slow and fast rotators and empirical constraints on spin-down torque mechanisms
• Three-temperature radiation hydrodynamics with PLUTO: Thermal and kinematic signatures of accreting protoplanets
• The protoplanetary disc around HD 169142: circumstellar or circumbinary?
• Asymmetric Temperature Variations In Protoplanetary disks: I. Linear Theory, Corotating Spirals, and Ring Formation
• The edge-on disk Tau042021: icy grains at high altitudes and a wind containing astronomical PAHs
• Hydrodynamical models of the $\beta$ Lyr A circumstellar disc
• Modelling shadows in scattered light observations as signals from companions in protoplanetary discs