Migration and the Formation of Systems of Hot Super-Earths and Neptunes

By C. Terquem, J. Papaloizou. 2006

281 citations recorded by the source corpus.

The existence of extrasolar planets with short orbital periods suggests that planetary migration induced by tidal interaction with the protoplanetary disk is important. Cores and terrestrial planets may undergo migration as they form. In this paper we investigate the evolution of a population of cores with initial masses in the range 0.1-1 M⊕ embedded in a disk. Mutual interactions lead to orbit crossing and mergers, so that the cores grow during their evolution. Interaction with the disk leads to orbital migration, which results in the cores capturing each other in mean motion resonances. As the cores migrate inside the disk inner edge, scatterings and mergers of planets on unstable orbits, together with orbital circularization, causes strict commensurability to be lost. Near commensurability however is usually maintained. All the simulations end with a population typically between two and five planets, with masses depending on the initial mass. These results indicate that if hot super-Earths or Neptunes form by mergers of inwardly migrating cores, then such planets are most likely not isolated. We would expect to always find at least one, more likely a few, companions on close and often near-commensurable orbits. To test this hypothesis, it would be of interest to look for planets of a few to about 10 M⊕ in systems where hot super-Earths or Neptunes have already been found.

Subfields: Astronomy and Astrophysics

View Paper: https://www.semanticscholar.org/paper/627c66216dff9c09f4a9b29883dbe16f2b521543

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Citations in the corpus

• Three-dimensional simulations of multiple protoplanets embedded in a protostellar disc (2008, background): “Terquem & Papaloizou (2007) suggest that near-commeasurabilities between protoplanets will survive beyond a disc edge, while experiments by Pierens & Nelson (2008) similarly indicate that a disc edge formed by the action of a close stellar binary companion can prevent the further migration of a…”
• Compositional Imprints in Density–Distance–Time: A Rocky Composition for Close-in Low-mass Exoplanets from the Location of the Valley of Evaporation (2017, background): “These icy planetary cores could then migrate to close-in orbits by disk-based migration (Goldreich & Tremaine 1980; Lin et al. 1996; Zhou et al. 2005) or migration due to the dynamics in the planetesimal disk (Terquem & Papaloizou 2007; Ji et al. 2011; Ormel et al. 2012).”
• The habitability of Proxima Centauri b. I. Irradiation, rotation and volatile inventory from formation to the present (2016, background): “…can be explained if planetary embryos formed at several AU, migrated inward to the inner edge of the protoplanetary disk and underwent a late phase of collisions (Terquem & Papaloizou 2007; Ida & Lin 2010; McNeil & Nelson 2010; Swift et al. 2013; Cossou et al. 2014; Izidoro & et al. 2016).”
• The Occurrence and Architecture of Exoplanetary Systems (2014, background): “However, disk migration theorists also seem capable of forming these systems (Terquem & Papaloizou 2007).”
• ARCHITECTURE OF KEPLER'S MULTI-TRANSITING SYSTEMS. II. NEW INVESTIGATIONS WITH TWICE AS MANY CANDIDATES (2012, background): “Another possibility is the action of tidal dissipation in the planet, pulling it towards the star and increasing the period ratio (Novak et al. 2003; Terquem & Papaloizou 2007).”
• Assessing the Habitability of the TRAPPIST-1 System Using a 3D Climate Model (2017, background): “An alternative idea is that the TRAPPIST-1 planets may have formed further out and then migrated to their current positions (Terquem & Papaloizou 2007), thus circumventing the pre-main-sequence runaway phase, and making it easier from them to retain primordial volatiles.”
• MIGRATION THEN ASSEMBLY: FORMATION OF NEPTUNE-MASS PLANETS INSIDE 1 AU (2011, background): “The quantitative agreement between observations and model is in striking contrast to the failures of traditional migrationbased models (Alibert et al. 2006; Terquem & Papaloizou 2007; Ida & Lin 2010) to match the same observations (McNeil & Nelson 2010).”
• Planet-Disk Interaction and Orbital Evolution (2012, background): “Simulations that explore short-period super-Earth formation and tidal interaction with the central star for disk models containing inner cavities have been presented by Terquem & Papaloizou (2007).”
• PLANETARY POPULATION SYNTHESIS COUPLED WITH ATMOSPHERIC ESCAPE: A STATISTICAL VIEW OF EVAPORATION (2014, background): “In reality, there is likely a population of close-in, low-mass planets that formed without H/He via planet impacts after the dissipation of the nebula (Terquem & Papaloizou 2007; Ormel et al. 2012).”
• THE CLIMATE OF HD 189733b FROM FOURTEEN TRANSITS AND ECLIPSES MEASURED BY SPITZER (2010, background): “…in the protoplanetary disk indicate that they should evolve out of mean-motion resonance, so the lack of detected transit-timing variations may not be surprising, especially for interior perturbing planets (Fabrycky 2009; Adams et al. 2008; Terquem and Papaloizou 2007; Papaloizou and Terquem 2010).”
• DISSIPATIVE DIVERGENCE OF RESONANT ORBITS (2012, background): “It is likely that torques associated with disk-driven migration often lead to resonant coupling, and it has been suggested that near-exact commensurability should be maintained as planets travel through their proto-planetary disks (Terquem & Papaloizou 2007; Cresswell & Nelson 2008).”
• EVIDENCE OF POSSIBLE SPIN–ORBIT MISALIGNMENT ALONG THE LINE OF SIGHT IN TRANSITING EXOPLANET SYSTEMS (2010, background): “Moreover, any multiple systems that migrate will likely be dynamically stable before the dissipation of their gaseous parent protoplanetary disk, but dynamically unstable after dissipation (Terquem & Papaloizou 2007; Ogihara & Ida 2009).”
• Spacing of Kepler Planets: Sculpting by Dynamical Instability (2015, background): “Dynamical Scuplting The formation of Kepler planets themselves is not yet understood and different theories have been proposed (Terquem & Papaloizou 2007; Ida & Lin 2010; Hansen & Murray 2012; Chiang & Laughlin 2013; Chatterjee & Tan 2014).”
• Toward a Deterministic Model of Planetary Formation. IV. Effects of Type I Migration (2008, background): “Cores that have migrated to the inner edge of the disk may also coagulate and form super-Earths (e.g., Terquem & Papaloizou 2007).”
• ARCHITECTURE AND DYNAMICS OF KEPLER'S CANDIDATE MULTIPLE TRANSITING PLANET SYSTEMS (2011, background): “In the Solar System, there is a known excess of satellite pairs near mean-motion resonance (MMR) (Goldreich 1965), and theoretical models of planet formation and migration suggest that this may be the case for exoplanets (e.g., Marcy et al. 2001; Terquem & Papaloizou 2007).”
• The HARPS search for southern extra-solar planets - XVII. Super-Earth and Neptune-mass planets in multiple planet systems HD 47 186 and HD 181 433 (2008, background): “Various processes can bring planets closer to the star: planet-disc interaction in the form of types I and II migration (e.g. Terquem & Papaloizou 2007), planet-planet interaction in the form of shepherding (e.g. Mandell et al. 2007), and scattering with subsequent circularization or the Kozai…”
• TIDALLY HEATED TERRESTRIAL EXOPLANETS: VISCOELASTIC RESPONSE MODELS (2009, background): “Terquem & Papaloizou (2007) analyze the dynamics of short period Hot Earths and find tides eventually break exact 2:1 resonances, but remain in near-resonance with nonzero eccentricities during later stage tidal dissipation.”