On the dynamics of dust grains in a hierarchical environment. I: Binary case
The authors study the stage of planet formation when the particulate material is still dispersed as (sub) millimeter-to-meter sized primordial aggregates. In particular, the authors investigate the response of particles in a protoplanetory disk with radius 100 AU around a solar-like star, in the field of perturbing companions in a range about 300-1600 AU. A series of numerical simulations of hierarchical configurations and gravitational and viscous forces was performed. The evolution of a massive dust disk around binary components is shown to depend mainly on the relative rotation of stellar companions, and on the temperature and mass of the circumstellar disk. These results demonstrate that for binary companions near the dust disk, the perturbations lead to enhanced accretion rate onto the primary, decreasing the lifetime of particles in the protoplanetary disk. As a result, the mass of the disk decreases faster, which leads to a longer lifetime for particles in the disk. In addition, binary companions can induce tidal arms in the dust phase of the disk. By this way, the authors show that the planet formation is, in fact, favoured in binary environment under the condition that the disk size is smaller than the tidal truncation limit for the system.
scientific article; zbMATH DE number 1496165