ANALYSIS OF THE INSTABILITY DUE TO GAS-DUST FRICTION IN PROTOPLANETARY DISKS

• Published in: The Astrophysical journal Vol. 817; no. 2; pp. 140 - 145
• Main Author: Shadmehri, Mohsen
• Format: Journal Article
• Language: English
• Published: United States The American Astronomical Society 01.02.2016
• Subjects: ACCRETION DISKS; accretion, accretion disks; ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; AXIAL SYMMETRY; COMPARATIVE EVALUATIONS; COSMIC DUST; COUPLING; DISTURBANCES; Dust; EFFICIENCY; FRICTION; GRAIN SIZE; Grains; GRAVITATION; instabilities; INSTABILITY; INTERSTELLAR GRAINS; LAYERS; MASS; Planet formation; PLANETS; planets and satellites: formation; PROTOPLANETS; SATELLITES; Stability
• ISSN: 0004-637X; 1538-4357
• DOI: 10.3847/0004-637X/817/2/140

ABSTRACT We study the stability of a dust layer in a gaseous disk subject to linear axisymmetric perturbations. Instead of considering single-size particles, however, the population of dust particles is assumed to consist of two grain species. Dust grains exchange momentum with the gas via the drag force and their self-gravity is also considered. We show that the presence of two grain sizes can increase the efficiency of the linear growth of drag-driven instability in the protoplanetary disks (PPDs). A second dust phase with a small mass, compared to the first dust phase, would reduce the growth timescale by a factor of two or more, especially when its coupling to the gas is weak. This means that once a certain amount of large dust particles form, even though it is much smaller than that of small dust particles, the dust layer becomes more unstable and dust clumping is accelerated. Thus, the presence of dust particles of various sizes must be considered in studies of dust clumping in PPDs where both large and small dust grains are present.