Related papers: Vertical Structure and Turbulent Saturation Level …
We report high-resolution measurements of three-dimensional (3D) turbulence in a rapidly rotating fluid. By decomposing the velocity field into a vertically averaged component and a three-dimensional residual, we show that each dominates…
Angular momentum transport within young massive protoplanetary discs may be dominated by self-gravity at radii where the disk is too weakly ionized to allow the development of the magneto-rotational instability. We use time-dependent…
We present results of a set of three-dimensional, general relativistic radiation magnetohydrodynamics simulations of thin accretion discs around a non-rotating black hole to test their thermal stability. We consider two cases, one that is…
Protoplanetary discs should exhibit a weak vertical variation in their rotation profiles. Typically this `vertical shear' issues from a baroclinic effect driven by the central star's radiation field, but it might also arise during the…
We present high-resolution zoom-in simulations of molecular clouds exposed to an interstellar radiation field and cosmic ray ionisation rate up to 1000 times stronger than that of the solar neighbourhood. We detail the evolution of the…
We model the vertical structure of magnetized accretion disks subject to viscous and resistive heating, and irradiation by the central star. We apply our formalism to the radial structure of magnetized accretion disks threaded by a poloidal…
Numerical simulations of global three-dimensional (3D), self-gravitating discs with a gap opened by an embedded planet are presented. The simulations are customised to examine planetary gap stability. Previous results, obtained by Lin &…
We analytically derive the expressions for the structure of the inner region of protoplanetary disks based on the results from the recent hydrodynamical simulations. The inner part of a disk can be divided into four regions: dust-free…
The destabilising effect of Hall diffusion in a Keplerian disc allows the MRI to occur for much lower ionisation levels than would otherwise be possible. However, simulations suggest that the consequences for the saturated state are not as…
We carry out a series of local, shearing box simulations of the outer regions of protoplanetary disks, where ambipolar diffusion is important due to low ionization levels, to better characterize the nature of turbulence and angular momentum…
We examine the linear stability of a flow threaded by a weak, vertical magnetic field in a disk with a keplerian rotation profile and a vertical stratification of the ionization degree as that predicted for vast portions of protoplanetary…
High-angular resolution observations at sub-millimeter/millimeter wavelengths of disks surrounding young stars have shown that their morphology is made of azimuthally-symmetric or point-symmetric substructures, in some cases with spiral…
The recurrent outbursts that characterise low-mass binary systems reflect thermal state changes in their associated accretion discs. The observed outbursts are connected to the strong variation in disc opacity as hydrogen ionises near 5000…
During early phases of a protoplanetary disks's life, gravitational instabilities can produce significant mass transport, can dramatically alter disk structure, can mix and shock-process gas and solids, and may be instrumental in planet…
Global three dimensional magnetohydrodynamic (MHD) simulations of turbulent accretion disks are presented which start from fully equilibrium initial conditions in which the magnetic forces are accounted for and the induction equation is…
We explore the linear stability of astrophysical discs exhibiting vertical shear, which arises when there is a radial variation in the temperature or entropy. Such discs are subject to a "vertical-shear instability", which recent nonlinear…
Protoplanetary disks are prone to several hydrodynamic instabilities. One candidate, Convective Overstability (COS), can drive radial semi-convection that may influence dust dynamics and planetesimal formation. However, the COS has…
Protoplanetary disks are mainly heated by radiation from the central star. Since the incident stellar flux at any radius is sensitive to the disk structure near that location, an unstable feedback may be present. Previous investigations…
Turbulence in protoplanetary disks affects planet formation in many ways. While small dust particles are mainly affected by the aerodynamical coupling with turbulent gas velocity fields, planetesimals and larger bodies are more affected by…
The vertical structure of stationary thin accretion discs is calculated from the energy balance equation with heat generation due to microscopic ion viscosity {\eta} and electron heat conductivity {\kappa}, both depending on temperature. In…