Papers
Topics
Authors
Recent
Gemini 2.5 Flash
Gemini 2.5 Flash
121 tokens/sec
GPT-4o
9 tokens/sec
Gemini 2.5 Pro Pro
47 tokens/sec
o3 Pro
4 tokens/sec
GPT-4.1 Pro
38 tokens/sec
DeepSeek R1 via Azure Pro
28 tokens/sec
2000 character limit reached

Metallicity dependence of dust growth in a protoplanetary disk (2404.05805v1)

Published 8 Apr 2024 in astro-ph.EP

Abstract: In the context of planet formation, growth from micron-sized grains to kilometer-sized planetesimals is a crucial question. Since the dust growth rate depends on the amount of dust, realizing planet formation scenarios based on dust growth is challenging in environments with low metallicity, i.e. less dust. We investigate dust growth during disk evolution, particularly focusing on the relationship with metallicity. We perform two-dimensional thin-disk hydrodynamic simulations to track the disk evolution over 300 kyr from its formation. The dust motion is solved separately from the gas motion, with its distribution changing due to drag forces from the gas. Dust size growth is also accounted for, with the magnitude of the drag force varying according to the dust size. We employ three models with metallicities of 1.0, 0.1, and 0.01 ${\rm Z}{\odot}$, i.e. dust-to-gas mass ratios of 10${-2}$, 10${-3}$, and 10${-4}$, respectively. In the disks with the metallicities $\ge0.1$ ${\rm Z}{\odot}$, the dust radii reach cm sizes, consistent with estimations from the dust growth timescale. Conversely, for the metallicity of 0.01 ${\rm Z}{\odot}$, the maximum dust size is only 10${-2}$ cm, with almost no growth observed across the entire disk scale ($\sim$100 au). At the metallicities $\ge0.1$ ${\rm Z}{\odot}$, the decoupling between grown dust and gas leads to non-uniform dust-to-gas mass ratios. However, deviations from the canonical value of this ratio have no impact on the gravitational instability of the disk. The formation of dust rings is confirmed in the innermost part of the disk ($\sim$10--30 au). The dust rings where the dust-to-gas mass ratio is enhanced, and the Stokes number reaches $\sim$0.1, are suitable environments for the streaming instability. We conjecture that planetesimal formation occurs through the streaming instability in these dust rings.

Summary

We haven't generated a summary for this paper yet.

X Twitter Logo Streamline Icon: https://streamlinehq.com