Takayuki Tanigawa¹, Akito Maruta², and Masahiro N. Machida²

¹Institute of Low Temperature Science, Hokkaido University, Sapporo 060-0819, Japan
²Department of Earth and Planetary Sciences, Kyushu University, Fukuoka 812-8581, Japan

We investigate the accretion of solid materials onto circumplanetary disks from heliocentric orbits rotating in protoplanetary disks, which is a key process for the formation of regular satellite systems. In the late stage of the gas-capturing phase of giant planet formation, the accreting gas from protoplanetary disks forms circumplanetary disks. Since the accretion flow toward the circumplanetary disks affects the particle motion through gas drag force, we use hydrodynamic simulation data for the gas drag term to calculate the motion of solid materials. We consider a wide range of size for the solid particles (10^-2-10⁶ m), and find that the accretion efficiency of the solid particles peaks around 10 m sized particles because energy dissipation of drag with circum-planetary disk gas in this size regime is most effective. The efficiency for particles larger than 10 m becomes lower because gas drag becomes less effective. For particles smaller than 10 m, the efficiency is lower because the particles are strongly coupled with the background gas flow, which prevents particles from accretion. We also find that the distance from the planet where the particles are captured by the circumplanetary disks is in a narrow range and well described as a function of the particle size.

Reference
Tanigawa T, Maruta A and Machida MN (2014) Accretion of Solid Materials onto Circumplanetary Disks from Protoplanetary Disks. The Astrophysical Journal 784:109.
[doi:10.1088/0004-637X/784/2/109]

Link to Article