RESONANT TRAPPING OF PLANETESIMALS BY PLANET MIGRATION: DEBRIS DISK CLUMPS AND VEGA'S SIMILARITY TO THE SOLAR SYSTEM

摘要: This paper describes a model that can explain the observed clumpy structures of debris disks. Clumps arise because after planetary system forms, its planets migrate angular momentum exchange with remaining planetesimals. Outward migration outermost planet traps planetesimals outside orbit into resonances, and resonant forces cause azimuthal structure in their distribution. The is based on numerical simulations different masses, Mpl, migrating at rates, pl, through dynamically cold (e < 0.01) planetesimal disk initially semimajor axis a. Trapping probabilities resulting are presented for planet's 2 : 1, 5 3, 3 2, 4 resonances. Seven possible dynamical identified from migrations defined by μ = Mpl/M* θ pl (a/*)1/2. Application this to 850 μm image Vega's shows two clumps unequal brightness be explained Neptune-mass 40 65 AU over 56 Myr; tight constraints set ranges these parameters. caused 1 resonances; asymmetry arises overabundance 1(u) 1(l) resonance. similarity proposed our own Neptune hints may much more akin solar than previously thought. Predictions made would substantiate model, such as orbital motion pattern, location planet, presence lower level clumps.