Testing planet formation from the ultraviolet to the millimeter

Abstract

Gaps imaged in protoplanetary discs are suspected to be opened by planets. We compute the present-day mass accretion rates ${\dot{M}}_{\mathrm{p}}$ of seven hypothesized gap-embedded planets, plus the two confirmed planets in the PDS 70 disc. The accretion rates are based on disc gas surface densities ${\Sigma }_{\mathrm{gas}}$ from C${}^{18}$O observations, and planet masses $M_{\mathrm{p}}$ from simulations fitted to observed gaps. Assuming accretion is Bondi-like, we find in eight out of nine cases that ${\dot{M}}_{\mathrm{p}}$ is consistent with the time-averaged value given by the current planet mass and system age, $M_{\mathrm{p}}/t_{\mathrm{age}}$. As system ages are comparable to circumstellar disc lifetimes, these gap-opening planets may be undergoing their last mass doublings, reaching final masses of $M_{\mathrm{p}}\sim 10-10^2{M}_{\oplus }$ for the non-PDS 70 planets, and $M_{\mathrm{p}}\sim 1-10M_{\mathrm{J}}$ for the PDS 70 planets. For another fifteen gaps without C${}^{18}$O data, we predict ${\Sigma }_{\mathrm{gas}}$ by assuming their planets are accreting at their time-averaged ${\dot{M}}_{\mathrm{p}}$. Bondi accretion rates for PDS 70b and c are orders of magnitude higher than accretion rates implied by measured U-band and H$\alpha$ fluxes, suggesting most of the accretion shock luminosity emerges in as yet unobserved wavebands, or that the planets are surrounded by dusty, highly extincting, quasi-spherical circumplanetary envelopes. Thermal emission from such envelopes or from circumplanetary discs, on Hill sphere scales, peaks at wavelengths in the mid-to-far-infrared and can reproduce observed mm-wave excesses.

Accepted to MNRAS. Discussion on PDS 70 moved to a new Section 3.3

References in corpus (39)

• New evolutionary models for pre-main sequence and main sequence low-mass stars down to the hydrogen-burning limit
• Two accreting protoplanets around the young star PDS 70
• Observations of Protoplanetary Disk Structures
• Molecules with ALMA at Planet-forming Scales (MAPS) I: Program Overview and Highlights
• A Three-Dimensional View of Turbulence: Constraints on Turbulent Motions in the HD 163296 Protoplanetary Disk using DCO${}^{+}$
• A Circumplanetary Disk Around PDS70c
• Three radial gaps in the disk of TW Hydrae imaged with SPHERE
• Multiple Disk Gaps and Rings Generated by a Single Super-Earth
• Submillimeter emission associated with candidate protoplanets
• Mass measurements in protoplanetary disks from hydrogen deuteride
• Molecules with ALMA at Planet-forming Scales (MAPS) V: CO gas distributions
• Gas density drops inside dust cavities of transitional disks around young stars observed with ALMA
• 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
• The newborn planet population emerging from ring-like structures in discs
• Constraining the Nature of the PDS 70 Protoplanets with VLTI/GRAVITY
• Hydrodynamics of embedded planets' first atmospheres - III. The role of radiation transport for super-Earth planets
• Water vapor distribution in protoplanetary disks
• Including Dust Coagulation in Hydrodynamic Models of Protoplanetary Disks: Dust Evolution in the Vicinity of a Jupiter-mass Planet
• A multi-frequency ALMA characterization of substructures in the GM Aur protoplanetary disk
• The circumstellar disk HD169142: gas, dust and planets acting in concert?
• Keck/NIRC2 $L$'-Band Imaging of Jovian-Mass Accreting Protoplanets around PDS 70
• VLT/SPHERE exploration of the young multiplanetary system PDS70
• Evidence for a circumplanetary disk around protoplanet PDS 70 b
• Mass Accretion onto T Tauri Stars
• Accretion Properties of PDS 70b with MUSE
• Perturbers: SPHERE detection limits to planetary-mass companions in protoplanetary disks
• Hubble Space Telescope UV and H$\alpha$ Measurements of the Accretion Excess Emission from the Young Giant Planet PDS 70 b
• The chemical inventory of the planet-hosting disk PDS 70
• The TW Hya Rosetta Stone Project III: Resolving the Gaseous Thermal Profile of the Disk
• Comparison of planetary Hα-emission models: A new correlation with accretion luminosity
• The End of Runaway: How Gap Opening Limits the Final Masses of Gas Giants
• Molecular mapping of the PDS70 system: No molecular absorption signatures from the forming planet PDS70 b
• How Consumption and Repulsion Set Planetary Gap Depths and the Final Masses of Gas Giants
• The Endgame of Gas Giant Formation: Accretion Luminosity and Contraction Post-Runaway
• High Spatial Resolution Observations of Molecular Lines towards the Protoplanetary Disk around TW Hya with ALMA
• Modeling the nonaxisymmetric structure in the HD 163296 disk with planet-disk interaction
• A search for companions via direct imaging in the DSHARP planet-forming disks
• Spectral appearance of the planetary-surface accretion shock: Global spectra and hydrogen-line profiles and fluxes

Cited by in corpus (2)

• The maximum accretion rate of a protoplanet: how fast can runaway be?
• Longterm Stability of Planetary Systems formed from a Transitional Disk