4:15 PM - 4:30 PM
[MGI30-10] Oligarchic growth of protoplanets in an expanding planetesimal ring
Keywords:Planet formation, N-body simulation
In the standard planet formation scenario, planetesimals have been assumed to form throughout the protoplanetary disk and to be smoothly distributed in the radial direction except for the snowline. Planetesimal evolution theory is also investigated based on this assumption. Recently, however, simulations of gas and dust evolution have shown that planetesimals form only in radially limited locations, such as gas pressure bumps and snowlines, and are concentrated in ring-like regions. On the other hand, simulations starting from protoplanets arranged in a narrow annulus successfully reproduced the mass distribution of terrestrial planets in the solar system. In addition, the existence of ring structures in the planet formation process has been supported by the observations of protoplanetary disks. The evolution process of planetesimals distributed in a ring is crucial to understanding planet formation theory. However, the evolution of planetesimal rings has not been studied in detail.
We investigate the evolution of a planetesimal ring. In the simulation, protoplanets undergo oligarchic growth while the ring expands. The ring width and the orbital distribution of protoplanets do not depend on the initial ring width. Moreover, protoplanets' mass and orbital separation between adjacent protoplanets in the ring can be predicted by the oligarchic growth model and the surface density after ring expansion. The ring expands more efficiently after protoplanets are formed than before. This is because protoplanets scatter planetesimals more intensively than planetesimals. In the presentation, we discuss the physics underlying planetesimal diffusion and its modeling.
We investigate the evolution of a planetesimal ring. In the simulation, protoplanets undergo oligarchic growth while the ring expands. The ring width and the orbital distribution of protoplanets do not depend on the initial ring width. Moreover, protoplanets' mass and orbital separation between adjacent protoplanets in the ring can be predicted by the oligarchic growth model and the surface density after ring expansion. The ring expands more efficiently after protoplanets are formed than before. This is because protoplanets scatter planetesimals more intensively than planetesimals. In the presentation, we discuss the physics underlying planetesimal diffusion and its modeling.