Oral Presentation
Accretion flows promote strong dust clumping in protoplanetary disks
Presenter: Shiang-Chih Wang (NTHU/ASIAA)
The streaming instability (SI) is a key mechanism for forming kilometer-sized planetesimals from dust or pebbles in the core accretion scenario of planet formation. In disks with a radial pressure gradient, the SI can locally enhance the dust-to-gas ratio, leading to gravitational collapse and helping to overcome both collisional and radial drift barriers. Recent studies have identified a new variant, the azimuthal-drift streaming instability (AdSI), which is driven by azimuthal accretion flows and can operate even in the absence of a radial pressure gradient.
In this study, we perform hydrodynamic simulations using an axisymmetric shearing box to investigate dust growth efficiency under varying strengths of azimuthal accretion flow. Our results suggest that in the non-clumping regime of the classical SI, azimuthal accretion flow enhances dust growth efficiency. In contrast, in the clumping regime, azimuthal accretion flow stabilizes the SI, thereby reducing growth efficiency.
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