Work

Planetesimal Formation under Realistic Gas Dynamics: Dust Concentration in Turbulent and Windy Protoplanetary Disks

Year: 2026

Type: article

Abstract: Planetesimals are a key intermediate stage of planet formation and originate from dust concentration in protoplanetary disks, which is strongly regulated by gas dynamics. In this study, we use the multifluid dust module of Athena++ to investigate dust concentration in 2D axisymmetric global nonideal magnetohydrodynamic (MHD) (ambipolar diffusion (AD)) simulations of outer disks. Our simulations simultaneously launch large-scale MHD disk winds and resolve both streaming instability (SI) and vertical shear instability (VSI). We systematically explore the effects of magnetic-field strength, cooling timescale, ambipolar Elsässer number, and dust size on dust concentration. We find that strong dust clumping persists across a broad range of magnetized and wind-launching disk conditions. MHD winds also enhance dust clumping by modifying background conditions in the following ways: (1) secular gas depletion by MHD wind mass loss and (2) dust trapping in zonal flows as a result of magnetic-flux concentration (which occurs in more strongly magnetized cases). Overall, our results demonstrate that strong dust clumping can persist in global magnetized disks with AD and large-scale MHD winds, leading to conditions favorable for planetesimal formation.

Source: The Astrophysical Journal Letters

DOI: 10.3847/2041-8213/aeaed9

Authors: Pinghui Huang, Xue-Ning Bai

Institutions: Chinese Academy of Sciences, Tsinghua University

Language: English

Topic: Astrophysics and Star Formation Studies

Subfield: Astronomy and Astrophysics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $2,400

Funders: National Natural Science Foundation of China, Chinese Academy of Sciences