On the Stability of Dust-Laden Protoplanetary Vortices

Abstract

The formation of planetesimals via gravitational instability of the dust layer in a protoplanetary disks demands that there be local patches where dust is concentrated by a factor of $\sim$ a few $\times 10^3$ over the background value. Vortices in protoplanetary disks may concentrate dust to these values allowing them to be the nurseries of planetesimals. The concentration of dust in the cores of vortices increases the dust-gas ratio of the core compared to the background disk, creating a "heavy vortex." In this work, we show that these vortices are subject to an instability which we have called the heavy-core instability. Using Floquet theory, we show that this instability occurs in elliptical protoplanetary vortices when the gas-dust density of the core of the vortex is heavier than the ambient gas-dust density by a few tens of percent. The heavy-core instability grows very rapidly, with a growth timescale of a few vortex rotation periods. While the nonlinear evolution of this instability remains unknown, it will likely increase the velocity dispersion of the dust layer in the vortex because instability sets in well before sufficient dust can gather to form a protoplanetary seed. This instability may thus preclude vortices from being sites of planetesimal formation.

11 pages, 9 figures, accepted to ApJ

References in corpus (8)

• Forming Planetesimals in Solar and Extrasolar Nebulae
• Particle Clumping and Planetesimal Formation Depend Strongly on Metallicity
• The subcritical baroclinic instability in local accretion disc models
• Planet formation bursts at the borders of the dead zone in 2D numerical simulations of circumstellar disks
• On the Stability of Elliptical Vortices in Accretion Discs
• Vertical Shearing Instabilities in Radially Shearing Disks: The Dustiest Layers of the Protoplanetary Nebula
• Three-Dimensional Simulations of Kelvin-Helmholtz Instability in Settled Dust Layers in Protoplanetary Disks
• Formation, Survival, and Destruction of Vortices in Accretion Disks

Cited by in corpus (22)

• Steady state of dust distributions in disk vortices: Observational predictions and applications to transitional disks
• Effects of dust feedback on vortices in protoplanetary disks
• Particle Trapping and Streaming Instability in Vortices
• Dust-trapping Rossby vortices in protoplanetary disks
• Formation and long-term evolution of 3D vortices in protoplanetary discs
• Rossby wave instability at dead zone boundaries in 3D resistive magnetohydrodynamical global models of protoplanetary disks
• Rossby Wave Instability in three dimensional discs
• Dust capture and long-lived density enhancements triggered by vortices in 2D protoplanetary disks
• Planet-induced Vortices with Dust Coagulation in Protoplanetary Disks
• ALMA Observations of the Asymmetric Dust Disk around DM Tau
• Gap and rings carved by vortices in protoplanetary dust
• Impact of Local Pressure Enhancements on Dust Concentration inTurbulent Protoplanetary Discs
• Cooling-Induced Vortex Decay in Keplerian Disks
• Rossby Wave Instability and Long-Term Evolution of Dead Zones in Protoplanetary Discs
• Dynamics of Dusty Vortices I: Extensions and limitations of the terminal velocity approximation
• An asymmetric dust ring around a very low mass star ZZ Tau IRS
• On the local stability of vortices in differentially rotating discs
• Vortex survival in 3D self-gravitating accretion discs
• A Possible Detection of Occultation by a Proto-planetary Clump in GM Cephei
• Positive Feedback: How a Synergy Between the Streaming Instability and Dust Coagulation Forms Planetesimals
• Dynamics of Dusty Vortices II: Stability of 2D dust laden vortices
• Positive Feedback II: How Dust Coagulation inside Vortices Can Form Planetesimals at Low Metallicity