Protostellar Cloud Fragmentation and Inward Migration by Disk Capture as the Origin of Massive Exoplanets

Abstract

A new model for the formation of Jovian planets is proposed. We consider planets forming at large distances from a protostar (>100 AU) through direct fragmentation of a gas cloud, by the same formation mechanism as wide stellar and brown dwarf binaries. We model the gravitational evolution of a system of these distant planets and a second population formed in a disk closer to the star. We compute the typical closest approach of these planets to the star (i.e., smallest pericenter) over the course of their evolution. When the planets reach a pericenter within a gaseous disk surroundig the star, dynamical friction from this disk slows down the planet at each plunge, causing its orbit to be gradually circularized and made coplanar with the disk. After the disk dissipates, a large fraction of these planets may be left at orbits small enough to be detected in present radial velocity surveys. A brief analytic derivation of the rate of orbital energy dissipation during these disk crossings is presented. Observational tests of this model are discussed.

27 pages, 8 figures

References in corpus (33)

• Disk Frequencies and Lifetimes in Young Clusters
• A Non-Gray Theory of Extrasolar Giant Planets and Brown Dwarfs
• Dynamical Outcomes of Planet-Planet Scattering
• Catalog of Nearby Exoplanets
• Discovery of a Cool Planet of 5.5 Earth Masses Through Gravitational Microlensing
• Dynamical Origin of Extrasolar Planet Eccentricity Distribution
• Can giant planets form by direct gravitational instability?
• A Super-Alfvenic Model of Dark Clouds
• Discovery of a Jupiter/Saturn Analog with Gravitational Microlensing
• Measurement of Spin-Orbit Alignment in an Extrasolar Planetary System
• Detection of Nine M8.0-L0.5 Binaries: The Very Low Mass Binary Population and its Implications for Brown Dwarf and VLM Star Formation
• Microlens OGLE-2005-BLG-169 Implies Cool Neptune-Like Planets are Common
• A correlation between the heavy element content of transiting extrasolar planets and the metallicity of their parent stars
• Atmospheres of protoplanetary cores: critical mass for nucleated instability
• The "Mysterious" Origin of Brown Dwarfs
• Misaligned spin-orbit in the XO-3 planetary system?
• The Mass of the Convective Zone in FGK Main Sequence Stars and the Effect of Accreted Planetary Material on Apparent Metallicity Determinations
• Migrating Planets
• Epsilon Indi Ba/Bb: the nearest binary brown dwarf
• Gravitational fragmentation and the formation of brown dwarfs in stellar clusters
• Substellar Companions to Main Sequence Stars: No Brown Dwarf Desert at Wide Separations
• Convective cooling and fragmentation of gravitationally unstable disks
• Dynamical Relaxation and Massive Extrasolar Planets
• The Eccentricity-Mass Distribution of Exoplanets: Signatures of Different Formation Mechanisms?
• Testing Disk Instability Models for Giant Planet Formation
• The substellar mass function in sigma Orionis. II. Optical, near-infrared and IRAC/Spitzer photometry of young cluster brown dwarfs and planetary-mass objects
• A Possible Spin-Orbit Misalignment in the Transiting Eccentric Planet HD 17156b
• Exoplanet detection capability of the COROT space mission
• Are Debris Disks and Massive Planets Correlated?
• Dynamical relaxation and the orbits of low-mass extrasolar planets
• From discs to planetesimals I: evolution of gas and dust discs
• Possible Observational Criteria for Distinguishing Brown Dwarfs from Planets
• Infrared spectroscopy of a brown dwarf companion candidate near the young star GSC 08047-00232 in Horologium

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