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arXiv · 1711.05948

Non-linear Development of Secular Gravitational Instability in Protoplanetary Disks

Ryosuke T. Tominaga·Shu-ichiro Inutsuka·Sanemichi Z. Takahashi
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Abstract

We perform non-linear simulation of secular gravitational instability (GI) in protoplanetary disks that has been proposed as a mechanism of the planetesimal formation and the 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 integrator. 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 one hundred while that of gas does not increase even by a factor of two, 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.

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Ryosuke T. Tominaga, Shu-ichiro Inutsuka, Sanemichi Z. Takahashi. 2017-11-16. Non-linear Development of Secular Gravitational Instability in Protoplanetary Disks. https://doi.org/10.1093/pasj%2Fpsx143

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