Related papers: Wave mediated angular momentum transport in astrop…
Hydrodynamical instabilities in disks around young stars depend on the thermodynamic stratification of the disk and on the local rate of thermal relaxation. Here, we map the spatial extent of unstable regions for the Vertical Shear…
We use local numerical simulations to investigate the strength and nature of magnetohydrodynamic (MHD) turbulence in the outer regions of protoplanetary disks, where ambipolar diffusion is the dominant non-ideal MHD effect. The simulations…
In this paper we briefly discuss the ways in which angular momentum transport is included in simulations of non-self-gravitating accretion disks, concentrating on disks in close binaries. Numerical approaches fall in two basic categories;…
We discuss the transport of angular momentum induced by tidal effects in a disk surrounding a star in a pre-main sequence binary system. We consider the effect of both density and bending waves. Although tidal effects are important for…
Turbulence can transport angular momentum in protoplanetary disks and influence the growth and evolution of planets. With spatially and spectrally resolved molecular emission line measurements provided by (sub)millimeter interferometric…
Layered accretion is one of the inevitable ingredients in protoplanetary disks when disk turbulence is excited by magnetorotational instabilities (MRIs). In the accretion, disk surfaces where MRIs fully operate have a high value of disk…
The magnetorotational instability (MRI) may dominate outward transport of angular momentum in accretion disks, allowing material to fall onto the central object. Previous work has established that the MRI can drive a mean-field dynamo,…
Accretion disks in which angular momentum transport is dominated by the magnetorotational instability (MRI) can also possess additional, purely hydrodynamic, drivers of turbulence. Even when the hydrodynamic processes, on their own,…
We propose that the strength of angular momentum transport in accretion discs threaded by net vertical magnetic field is determined by a self-regulation mechanism: the magnetorotational instability (MRI) grows until its own turbulent…
Identifying the mechanisms responsible for angular momentum transport in protoplanetary disks, and the extent to which those mechanisms produce turbulence, is a crucial problem in understanding planet formation. The bulk of the gas in…
Until a decade ago, galaxy formation simulations were unable to simultaneously reproduce the observed angular momentum (AM) of galaxy disks and bulges. Improvements in the interstellar medium and stellar feedback modelling, together with…
Asteroseismic measurements of the internal rotation rate in evolved stars pointed out to a lack of angular momentum (AM) transport in stellar evolution models. Several physical processes in addition to hydrodynamical ones were proposed as…
We present analytic calculations of angular momentum transport and gas inflow in galaxies, from scales of ~kpc to deep in the potential of a central black hole (BH). We compare these analytic calculations to numerical simulations and use…
Angular momentum loss (AML) mechanisms and dynamical evolution owing to magnetic braking and gravitational radiation in relativistic binary stars (RBS) are studied with use of physical parameters collected from the literature. We have…
The magnetorotational instability (MRI) (Balbus and Hawley 1991, Hawley and Balbus 1991) transports angular momentum radially outwards in accretion discs through the distortion of the magnetic field lines that connect fluid elements. In…
The mechanism of turbulent viscosity is the central question in investigations of turbulence. This is also the case in the accretion disk theory, where turbulence is considered to be responsible for the outward transport of angular momentum…
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…
We study the dynamical effects of gravitational focusing by a binary companion on winds from late-type stars. In particular, we investigate the mass transfer and formation of accretion disks around the secondary in detached systems…
(abridged) We study the nonlinear evolution of the Rossby wave instability in thin disks using global 2D hydrodynamic simulations. The key questions we are addressing in this paper are: (1) What happens when the instability becomes…
Circumstellar discs around Be stars are formed by the material ejected by the central star. This process removes excess angular momentum from the star as viscosity facilitates the mass and angular momentum transfer within the disc and its…