Non-linear development of secular gravitational instability in protoplanetary disks

PASJ: Publications of the Astronomical Society of Japan

Takahashi, Sanemichi Z¹  Tominaga, Ryosuke T²  Inutsuka, Shu-ichiro² 

[1] Astronomical Institute, Tohoku University, 6-3 Aoba, Aramaki, Aoba-ku, Sendai, Miyagi 980-8578, Japan;Department of Physics, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8602, Japan

关键词: instabilities;    methods: numerical;    protoplanetary disks;   

DOI  :  10.1093/pasj/psx143

学科分类：天文学(综合)

来源: Oxford University Press

【 摘 要 】

We perform non-linear simulation of secular gravitational instability (GI) in protoplanetary disks, which has been proposed as a mechanism of planetesimal and multiple ring formation. Since the timescale of the growth of the secular GI is much longer than the Keplerian rotation period, we develop a new numerical scheme for a long-term calculation utilizing the concept of symplectic integration. With our new scheme, we first investigate the non-linear development of the secular GI in a disk without a pressure gradient in the initial state. We find that the surface density of dust increases by more than a factor of 100 while that of gas does not increase even by a factor of 2, which results in the formation of dust-dominated rings. A line mass of the dust ring tends to be very close to the critical line mass of a self-gravitating isothermal filament. Our results indicate that the non-linear growth of the secular GI provides a powerful mechanism to concentrate the dust. We also find that the dust ring formed via the non-linear growth of the secular GI migrates inward with a low velocity, which is driven by the self-gravity of the ring. We give a semi-analytical expression for the inward migration speed of the dusty ring.

【 授权许可】

CC BY