Non-linear development of secular gravitational instability in protoplanetary disks
Abstract
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.
- Publication:
-
Publications of the Astronomical Society of Japan
- Pub Date:
- January 2018
- DOI:
- 10.1093/pasj/psx143
- arXiv:
- arXiv:1711.05948
- Bibcode:
- 2018PASJ...70....3T
- Keywords:
-
- instabilities;
- methods: numerical;
- protoplanetary disks;
- Astrophysics - Earth and Planetary Astrophysics
- E-Print:
- 29 pages, 18 figures, accepted for publication in Publications of the Astronomical Society of Japan