The Separation and H-alpha Contrasts of Massive Accreting Planets in the Gaps of Transitional Disks: Predicted H-alpha Protoplanet Yields for Adaptive Optics Surveys

Abstract

We present a massive accreting gap (MAG) planet model that ensures large gaps in transitional disks are kept dust free by the scattering action of three co-planar quasi-circular planets in a 1:2:4 Mean Motion Resonance (MMR). This model uses the constraint of the observed gap size, and the dust-free nature of the gap, to determine within ~10% the possible orbits for 3 massive planets in an MMR. Calculated orbits are consistent with the observed orbits and H-alpha emission (the brightest line to observe these planets) for LkCa 15 b and PDS 70 b and PDS 70 c within observational errors. Moreover, the model suggests that the scarcity of detected H-alpha planets is likely a selection effect of the current limitations of non-coronagraphic, low (<10%) Strehl, H-alpha imaging with Adaptive Optics (AO) systems used in past H-alpha surveys. We predict that as higher Strehl AO systems (with high-performance custom coronagraphs; like 6.5-m Magellan Telescope MagAO-X system) are utilized at H-alpha the number of detected gap planets will substantially increase by more than tenfold. For example, we show that >25 new H-alpha "gap planets" are potentially discoverable by a survey of the best 19 transitional disks with MagAO-X. Detections of these accreting protoplanets will significantly improve our understanding of planet formation, planet growth and accretion, solar system architectures, and planet disk interactions.

36 pages, 8 Figures, Accepted by the Astronomical Journal

References in corpus (21)

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• The widest H$\alpha$ survey of accreting protoplanets around nearby transition disks
• Shock-driven Accretion in Circumplanetary Disks: Observables and Satellite Formation
• An ALMA and MagAO Study of the Substellar Companion GQ Lup B
• Detectability of embedded protoplanets from hydrodynamical simulations
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• Spectral Energy Distributions of Accreting Protoplanets
• The Planetary Luminosity Problem: "Missing Planets" and the Observational Consequences of Episodic Accretion
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Cited by in corpus (13)

• A stellar mass dependence of structured disks: a possible link with exoplanet demographics
• Hubble Space Telescope UV and H$\alpha$ Measurements of the Accretion Excess Emission from the Young Giant Planet PDS 70 b
• Comparison of planetary Hα-emission models: A new correlation with accretion luminosity
• Transition disks: the observational revolution from SEDs to imaging
• HST/WFC3 H$\alpha$ Direct-Imaging Detection of a Point-like Source in the Disk Cavity of AB Aur
• Accreting protoplanets: Spectral signatures and magnitude of gas and dust extinction at H alpha
• The Giant Accreting Protoplanet Survey (GAPlanetS) -- Results from a Six Year Campaign to Image Accreting Protoplanets
• Searching for H${}_{\alpha }$-emitting sources in the gaps of five transitional disks. SPHERE/ZIMPOL high-contrast imaging
• The vector-apodizing phase plate coronagraph: design, current performance, and future development
• The Planetary Accretion Shock. III. Smoothing-free 2.5D simulations and calculation of H alpha emission
• Three Years of High-Contrast Imaging of the PDS 70 b and c Exoplanets at Hα with MagAO-X: Evidence of Strong Protoplanet Hα Variability and Circumplanetary Dust
• Occurrence rates of accreting companions from a new method for computing emission-line survey sensitivity: application to the H-alpha Giant Accreting Protoplanet Survey
• Semianalytical Accretion-Tracer Emission: Forming Planets Are Intrinsically Faint