How Bright are Planet-Induced Spiral Arms in Scattered Light?

Abstract

Recently, high angular resolution imaging instruments such as SPHERE and GPI have discovered many spiral-arm-like features in near-infrared scattered light images of protoplanetary disks. Theory and simulations have suggested that these arms are most likely excited by planets forming in the disks; however, a quantitative relation between the arm-to-disk brightness contrast and planet mass is still missing. Using 3D hydrodynamics and radiative transfer simulations, we examine the morphology and contrast of planet-induced arms in disks. We find a power-law relation for the face-on arm contrast (${\delta }_{\max }$) as a function of planet mass ($M_{\mathrm{p}}$) and disk aspect ratio ($h/r$): ${\delta }_{\max }\approx ((M_{\mathrm{p}}/M_{\mathrm{J}})/(h/r{)}^{1.38}{)}^{0.22}$. With current observational capability, at a 30 AU separation, the minimum planet mass for driving detectable arms in a disk around a 1 Myr 1$M_{\odot }$ star at 140 pc at low inclinations is around Saturn mass. For planets more massive than Neptune masses, they typically drive multiple arms. Therefore in observed disks with spirals, it is unlikely that each spiral arm originates from a different planet. We also find only massive perturbers with at least multi-Jupiter masses are capable of driving bright arms with ${\delta }_{\max }\gtrsim 2$ as found in SAO 206462, MWC 758, and LkH$\alpha$~330, and these arms do not follow linear wave propagation theory. Additionally, we find the morphology and contrast of the primary and secondary arms are largely unaffected by a modest level of viscosity with $\alpha \lesssim 0.01$. Finally, the contrast of the arms in the SAO 206462 disk suggests that the perturber SAO 206462 b at $\sim 100$ AU is about $5-10M_{\mathrm{J}}$ in mass.

37 pages, 14 figures, 1 table; ApJ published

References in corpus (16)

• Gravitational Instabilities in Circumstellar Disks
• Asymmetric features in the protoplanetary disk MWC758
• Direct Imaging of Fine Structures in Giant Planet Forming Regions of the Protoplanetary Disk around AB Aurigae
• Hall-effect Controlled Gas Dynamics in Protoplanetary Disks: II. Full 3D Simulations toward the Outer Disk
• The minimum mass of detectable planets in protoplanetary discs and the derivation of planetary masses from high resolution observations
• Gas density drops inside dust cavities of transitional disks around young stars observed with ALMA
• Dust Trapping by Vortices in Transitional Disks: Evidence for Non-ideal MHD Effects in Protoplanetary Disks
• Recovery of the Candidate Protoplanet HD 100546 b with Gemini/NICI and Detection of Additional (Planet-Induced?) Disk Structure at Small Separations
• HD100546 Multi-Epoch Scattered-Light Observations
• Slowly-growing gap-opening planets trigger weaker vortices
• Scattered light mapping of protoplanetary disks
• Spiral Structure and Differential Dust Size Distribution in the LkHa 330 Disk
• Self-Destructing Spiral Waves: Global Simulations of a Spiral Wave Instability in Accretion Disks
• Extreme Asymmetry in the Disk of V1247 Ori
• Ultraharmonics and Secondary Spiral Wakes Induced by a Planet
• Spirals in protoplanetary disks from photon travel time

Cited by in corpus (50)

• Multiple Disk Gaps and Rings Generated by a Single Super-Earth
• The Eccentric Cavity, Triple Rings, Two-Armed Spirals, and Double Clumps of the MWC 758 Disk
• Evidence for a massive dust-trapping vortex connected to spirals: a multi-wavelength analysis of the HD~135344B protoplanetary disk
• Discovery of a point-like source and a third spiral arm in the transition disk around the Herbig Ae star MWC 758
• Planet-driven spiral arms in protoplanetary disks: I. Formation mechanism
• Spiral Arms in Disks: Planets or Gravitational Instability?
• Perturbers: SPHERE detection limits to planetary-mass companions in protoplanetary disks
• Planet-driven spiral arms in protoplanetary disks: II. Implications
• Variable dynamics in the inner disk of HD 135344B revealed with multi-epoch scattered light imaging
• Dust traps in the protoplanetary disc MWC 758: two vortices produced by two giant planets?
• Testing giant planet formation in the transitional disk of SAO 206462 using deep VLT/SPHERE imaging
• Diverse protoplanetary disk morphology produced by a Jupiter-mass planet
• The widest H$\alpha$ survey of accreting protoplanets around nearby transition disks
• Is the ring inside or outside the planet?: The effect of planet migration on dust rings
• Predicting the kinematic evidence of gravitational instability
• Thermal Infrared Imaging of MWC 758 with the Large Binocular Telescope: Planetary Driven Spiral Arms?
• Spiral arms in thermally stratified protoplanetary discs
• Gaps and Rings in Protoplanetary Disks with Realistic Thermodynamics: The Critical Role of In-Plane Radiation Transport
• ALMA Reveals a Misaligned Inner Gas Disk inside the Large Cavity of a Transitional Disk
• Dynamical Evidence of a Spiral Arm--Driving Planet in the MWC 758 Protoplanetary Disk
• Multiple Spiral Arms in Protoplanetary Disks: Linear Theory
• Herbig Stars: A Quarter Century of Progress
• The Planetary Luminosity Problem: "Missing Planets" and the Observational Consequences of Episodic Accretion
• Observational Signatures of Planets in Protoplanetary Disks: Planet-Induced Line Broadening in Gaps
• The Observability Of Vortex-Driven Spiral Arms In Protoplanetary Disk: Basic Spiral Properties
• A single-armed spiral in the protoplanetary disk around HD34282 ?
• Disk Accretion Driven by Spiral Shocks
• Investigating Protoplanetary Disk Cooling through Kinematics: Analytical GI Wiggle
• Three-temperature radiation hydrodynamics with PLUTO: Tests and applications to protoplanetary disks
• Spiral Arm Pattern Motion in the SAO 206462 Protoplanetary Disk
• DZ Cha: a bona fide photoevaporating disc
• Exciting spiral arms in protoplanetary discs from flybys
• A Simple Time-Dependent Method for Calculating Spirals: Applications to Eccentric Planets in Protoplanetary discs
• exoALMA. XVII. Characterizing the Gas Dynamics around Dust Asymmetries
• External or internal companion exciting the spiral arms in CQ Tau?
• Constraining the masses of planets in protoplanetary discs from the presence or absence of vortices -- Comparison with ALMA observations
• Three-temperature radiation hydrodynamics with PLUTO: Thermal and kinematic signatures of accreting protoplanets
• Imaging the 44 AU Kuiper Belt-analogue debris ring around HD 141569A with GPI polarimetry
• Testing velocity kinks as a planet-detection method: Do velocity kinks in surface gas emission trace planetary spiral wakes in the midplane continuum?
• Density waves in protoplanetary discs excited by eccentric planets: linear theory
• An extended scattered light disk around AT Pyx -- Possible planet formation in a cometary globule
• Can gap-edge illumination excite spirals in protoplanetary disks? Three-temperature radiation hydrodynamics and NIR image modelling
• Direct Measurement of Extinction in a Planet-Hosting Gap
• Distributions of gas and small and large grains in the LkH$\alpha 330$ disk trace a young planetary system
• Primordial dust rings, hidden dust mass, and the first generation of planetesimals in gravitationally unstable protoplanetary disks
• Multiple Rings and Asymmetric Structures in the Disk of SR 21
• Observable scattered light features from inclined and non-inclined planets embedded in protoplanetary discs
• Direct Imaging for the Debris Disk around $\epsilon$ Eridani with the Cool-Planet Imaging Coronagraph
• Searching for planet-driven dust spirals in ALMA visibilities
• Observational Signatures of Planets in Protoplanetary Disks: Temperature structures in spiral arms