Protostars and Planets VI, Heidelberg, July 15-20, 2013
GAP STRUCTURE AROUND PLANETS IN PROTOPLANETARY DISKS,
Kanagawa, Kazuhiro (ILTS, Hokkaido University)
Muto, Takayuki (Kogakuin University)
Tanaka, Hidekazu (ILTS, Hokkaido University)
Tanigawa, Takayuki (ILTS, Hokkaido University)
Takeuchi, Taku (Tokyo Institute of Technology)
In a protoplanetary disk, a large planet is able to create a gap, which is a low surface density annulus region along the planet orbit, by a gravitational interaction with the disk. If the planet is massive enough, the gap terminates the gaseous inflow across the orbit of planet. Thus, the gap formation is thought to be a possible mechanism that creates the transitional disks with the inner holes, which have been revealed by SED observations and direct imaging.
The formation of the disk gap also influences the planet itself. Because of the gap formation, the mode of the planet migration changes from Type I to II. The gap also fairly reduces the gas accretion into the planet. Since such a co-evolution of a protoplanetary disk and planets would be a key process that governs the origin of the diversity of exo-planetary systems, it has been studied by many authors. However, the co-evolution of a protoplanetary disk and planets still has a large uncertainty because of the complexity of the gap formation.
In this study, we examined the surface density profile of the gap, by using one-dimensional viscous accretion disk model with a simple model of a planet torque. In our calculation, we did not assume the Keplerian disk rotation, and took into account the disk rotation law altered by the steep surface density gradient in the gap, in a self-consistent way. We found that the altered rotation law significantly affects the resultant surface density profile especially for narrow and deep gaps.
Furthermore, we checked our one-dimensional gap calculation by performing two-dimensional hydrodynamical simulations of gap formation with the FARGO code, for various planet masses, and disk parameters (i.e., the disk scale height and the viscosity). Our one-dimensional gap calculation can reproduce precisely results of the hydrodynamic simulations for wide range of the planet mass and disk parameters.
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