Turbulent Dust-trapping Rings as Efficient Sites for Planetesimal Formation

Xu, Ziyan and Bai, Xue-Ning (2022) Turbulent Dust-trapping Rings as Efficient Sites for Planetesimal Formation. The Astrophysical Journal Letters, 937 (1). L4. ISSN 2041-8205

[thumbnail of Xu_2022_ApJL_937_L4.pdf] Text
Xu_2022_ApJL_937_L4.pdf - Published Version

Download (1MB)

Abstract

Recent observations of protoplanetary disks (PPDs) at submillimeter wavelengths have revealed the ubiquity of annular substructures that are indicative of pebble-sized dust particles trapped in turbulent ringlike gas pressure bumps. This major paradigm shift also challenges the leading theory of planetesimal formation from such pebbles by means of the streaming instability, which operates in a pressure gradient and can be suppressed by turbulence. Here, we conduct 3D local shearing box nonideal magnetohydrodynamic simulations of dust trapping in enforced gas pressure bumps, including dust backreaction. Under a moderate level of turbulence generated by the magnetorotational instability with ambipolar diffusion, which is suitable for outer disk conditions, we achieve quasi-steady states of dust trapping balanced by turbulent diffusion. We find strong dust clumping in all simulations near the gas pressure maxima, reaching a maximum density well above the threshold for triggering gravitational collapse to form planetesimals. A strong pressure bump concentrates dust particles toward the bump's center. With a weak pressure bump, dust can also concentrate in secondary filaments off the bump's center, due to dust backreaction, but strong clumping still occurs mainly in the primary ring around the bump's center. Our results reveal dust-trapping rings to be robust locations for planetesimal formation in outer PPDs, while they may possess diverse observational properties.

Item Type: Article
Subjects: STM Repository > Physics and Astronomy
Depositing User: Managing Editor
Date Deposited: 26 Apr 2023 04:58
Last Modified: 08 Mar 2024 04:26
URI: http://classical.goforpromo.com/id/eprint/3046

Actions (login required)

View Item
View Item