The baroclinic instability in the context of layered accretion. Self-sustained vortices and their magnetic stability in local compressible unstratified models of protoplanetary disks

Abstract

Turbulence and angular momentum transport in accretion disks remains a topic of debate. With the realization that dead zones are robust features of protoplanetary disks, the search for hydrodynamical sources of turbulence continues. A possible source is the baroclinic instability (BI), which has been shown to exist in unmagnetized non-barotropic disks. We present shearing box simulations of baroclinicly unstable, magnetized, 3D disks, in order to assess the interplay between the BI and other instabilities, namely the magneto-rotational instability (MRI) and the magneto-elliptical instability. We find that the vortices generated and sustained by the baroclinic instability in the purely hydrodynamical regime do not survive when magnetic fields are included. The MRI by far supersedes the BI in growth rate and strength at saturation. The resulting turbulence is virtually identical to an MRI-only scenario. We measured the intrinsic vorticity profile of the vortex, finding little radial variation in the vortex core. Nevertheless, the core is disrupted by an MHD instability, which we identify with the magneto-elliptic instability. This instability has nearly the same range of unstable wavelengths as the MRI, but has higher growth rates. In fact, we identify the MRI as a limiting case of the magneto-elliptic instability, when the vortex aspect ratio tends to infinity (pure shear flow). We conclude that vortex excitation and self-sustenance by the baroclinic instability in protoplanetary disks is viable only in low ionization, i.e., the dead zone. Our results are thus in accordance with the layered accretion paradigm. A baroclinicly unstable dead zone should be characterized by the presence of large-scale vortices whose cores are elliptically unstable, yet sustained by the baroclinic feedback. As magnetic fields destroy the vortices and the MRI outweighs the BI, the active layers are unmodified.

19+3 pages, 20+1 figures. Accepted by A&A, final version

References in corpus (12)

• 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
• Baroclinic Vorticity Production in Protoplanetary Disks; Part II: Vortex Growth and Longevity
• New composite models of partially ionized protoplanetary disks
• Global magnetohydrodynamical models of turbulence in protoplanetary disks I. A cylindrical potential on a Cartesian grid and transport of solids
• Vortices in Thin, Compressible, Unmagnetized Disks
• Energetic Protons, Radionuclides and Magnetic Activity in Protostellar Disks
• On the viability of the shearing box approximation for numerical studies of MHD turbulence in accretion disks
• On Hydrodynamic Motions in Dead Zones
• Transient growth and coupling of vortex and wave modes in self-gravitating gaseous discs
• Linear coupling of modes in 2D radially stratified astrophysical discs

Cited by in corpus (74)

• Wind-driven Accretion in Protoplanetary Disks. I: Suppression of the Magnetorotational Instability and Launching of the Magnetocentrifugal Wind
• Turbulence in the TW Hya Disk
• Possible planet-forming regions on submillimetre images
• Global Simulations of the Inner Regions of Protoplanetary Disks with Comprehensive Disk Microphysics
• A planetesimal orbiting within the debris disc around a white dwarf star
• A review of the disc instability model for dwarf novae, soft X-ray transients and related objects
• Convective Overstability in radially stratified accretion disks under thermal relaxation
• Hall-effect Controlled Gas Dynamics in Protoplanetary Disks: I. Wind Solutions at the Inner Disk
• Steady state of dust distributions in disk vortices: Observational predictions and applications to transitional disks
• Zombie Vortex Instability I: A Purely Hydrodynamic Instability to Resurrect the Dead Zones of Protoplanetary Disks
• Dust-trapping Rossby vortices in protoplanetary disks
• Convective overstability in accretion disks: 3D linear analysis and nonlinear saturation
• Particle Trapping and Streaming Instability in Vortices
• Temperature, Mass and Turbulence: A Spatially Resolved Multi-Band Non-LTE Analysis of CS in TW~Hya
• Formation and long-term evolution of 3D vortices in protoplanetary discs
• The initial conditions for planet formation: Turbulence driven by hydrodynamical instabilities in disks around young stars
• Planetesimal Population Synthesis: Pebble Flux Regulated Planetesimal Formation
• Rossby wave instability at dead zone boundaries in 3D resistive magnetohydrodynamical global models of protoplanetary disks
• The formation of the solar system
• A Parameter Study for Baroclinic Vortex Amplification
• Mapping the Conditions for Hydrodynamic Instability on Steady State Accretion Models of Protoplanetary Disks
• Efficiency of thermal relaxation by radiative processes in protoplanetary discs: constraints on hydrodynamic turbulence
• Vortex Formation and Survival in Protoplanetary Disks subject to Vertical Shear Instability
• Elliptical instability in hot Jupiter systems
• Rossby wave instability does not require sharp resistivity gradients
• Dust capture and long-lived density enhancements triggered by vortices in 2D protoplanetary disks
• Is the ring inside or outside the planet?: The effect of planet migration on dust rings
• Grand challenges in protoplanetary disc modelling
• Toroidal vortices and the conglomeration of dust into rings in protoplanetary discs
• Dead Zones around Young Stellar Objects: FU Orionis Outbursts and Transition Discs
• The negative effective magnetic pressure in stratified forced turbulence
• Macroscopic Dust in Protoplanetary Disks - From Growth to Destruction
• Global Simulations of the Vertical Shear Instability with Non-ideal Magnetohydrodynamical Effects
• Recent developments in planet migration theory
• The Sandwich Mode for Vertical Shear Instability in Protoplanetary Disks
• Pebble trapping in vortices: three-dimensional simulations
• Vortex cycles at the inner edges of dead zones in protoplanetary disks
• Testing large-scale vortex formation against viscous layers in three-dimensional discs
• Colliding Decimetre Dust
• Radiation thermo-chemical models of protoplanetary disks. Grain and polycyclic aromatic hydrocarbon charging
• The effect of a strong pressure bump in the Sun's natal disk: Terrestrial planet formation via planetesimal accretion rather than pebble accretion
• Cm-wavelength observations of MWC758: resolved dust trapping in a vortex
• Formation of Comets
• Turbulence in outer protoplanetary disks: MRI or VSI?
• Vortex stretching in self-gravitating protoplanetary discs
• Impact of Local Pressure Enhancements on Dust Concentration inTurbulent Protoplanetary Discs
• Cooling-Induced Vortex Decay in Keplerian Disks
• Shedding Light on the Eccentricity Valley: Gap Heating and Eccentricity Excitation of Giant Planets in Protoplanetary Disks
• Vortices in stratified protoplanetary disks : From baroclinic instability to vortex layers
• On shocks driven by high-mass planets in radiatively inefficient disks. I. Two-dimensional global disk simulations
• Formation of Terrestrial Planets
• The gravo-magneto disc instability with a viscous dead zone
• Critical layers and protoplanetary disk turbulence
• Planetesimal formation in self-gravitating discs -- dust trapping by vortices
• On the Anisotropic Nature of MRI-Driven Turbulence in Astrophysical Disks
• Interpreting Brightness Asymmetries in Transition Disks: Vortex at Dead Zone or Planet Carved Gap Edges?
• Axisymmetric simulations of the convective overstability in protoplanetary discs
• On the local stability of vortices in differentially rotating discs
• On the connection between the magneto-elliptic and magneto-rotational instabilities
• Vortex survival in 3D self-gravitating accretion discs
• Instabilities and Flow Structures in Protoplanetary Disks: Setting the Stage for Planetesimal Formation
• Constraining the masses of planets in protoplanetary discs from the presence or absence of vortices -- Comparison with ALMA observations
• Collisions of solid ice in planetesimal formation
• MRI-driven angular momentum transport in protoplanetary disks
• Extreme Pebble Accretion in Ringed Protoplanetary Discs
• Linear Corotation Torques in Non-Barotropic Disks
• On the vortex evolution in non-isothermal protoplanetary discs
• Photoevaporation of the Jovian circumplanetary disk I. Explaining the orbit of Callisto and the lack of outer regular satellites
• Photophoresis in the circumjovian disk and its impact on the orbital configuration of the Galilean satellites
• Potential vorticity dynamics in the framework of disk shallow-water theory: II. Mixed Barotropic-Baroclinic Instability
• The evolution of a circumplanetary disc with a dead zone
• Elliptic and magneto-elliptic instabilities of disk vortices
• Planetary nurseries: vortices formed at smooth viscosity transition
• Positive Feedback II: How Dust Coagulation inside Vortices Can Form Planetesimals at Low Metallicity