Related papers: Ambipolar Drift in a Turbulent Medium
We show that radiation dominated accretion discs are likely to suffer from a ``photon bubble'' instability similar to that described by Arons in the context of accretion onto neutron star polar caps. The instability requires a magnetic…
Increasingly sophisticated observational tools and techniques are now being developed for probing the nature of interstellar turbulence. At the same time, theoretical advances in understanding the nature of turbulence and its effects on the…
The interstellar thick disks of galaxies contain not only gas, but significant quantities of dust. Most of our knowledge of extraplanar dust in disk galaxies comes from direct broadband optical imaging of these systems, wherein the dust is…
Expanding our previous work on turbulent whirls [1] we have uncovered a similarity within the similarity shared by intense vortices. Using the new information we compress the tangential velocity profiles of a diverse set of vortices into…
Recent work on the structure of magnetic fields in a turbulent medium gives predictions for the properties of the magnetic flux tubes as a function of the Mach number and scale of the turbulence, and the resistivity and viscosity of the…
Magnetic fields are a dynamically important component of the turbulent interstellar medium (ISM) of star-forming galaxies. These magnetic fields are due to a dynamo action, which is a process of converting turbulent kinetic energy to…
We propose to interpret the stellar IMF as a property of the turbulence in the star--forming gas. Gravitationally unstable density enhancements in the turbulent flow collapse and form stars. Their mass distribution can be derived…
Theoretical and observational studies on the turbulence of the interstellar medium developed fast in the past decades. The theory of supersonic magnetized turbulence, as well as the understanding of projection effects of observed…
We seek to obtain a picture of the interstellar magnetic field in the Galactic center region that is as clear and complete as possible. To that end, we review the observational knowledge that has built up over the past 25 years on…
Accretion disks are likely threaded by external vertical magnetic flux, which enhances the level of turbulence via the magnetorotational instability (MRI). Using shearing-box simulations, we find that such external magnetic flux also…
Using numerical methods, we systematically study in the framework of ideal MHD the effect of magnetic fields on heat transfer within a turbulent gas. We measure the rates of passive scalar diffusion within magnetized fluids and make the…
A subsonic flow of an ideal gas through a flat channel in the presence of a mass force field is considered. The forces acting on the gas are reduced to the attraction to the channel axis in a certain region of the channel. It has been shown…
Instabilities of the dust layer in a protoplanetary disk are investigated. It is known that the streaming instability develops and dust density concentration occurs in a situation where the initial dust density is uniform. This work…
The magnetic field of a host star can impact the orbit of a stellar partner, planet, or asteroid if the orbiting body is itself magnetic or electrically conducting. Here, we focus on the instantaneous magnetic forces on an orbiting body in…
Accretion discs are composed of ionized gas in motion around a central object. Sometimes, the disc is the source of powerful bipolar jets along its rotation axis. Theoretical models invoke the existence of a bipolar magnetic field crossing…
The radio frequency 1.4 GHz transition of the atomic hydrogen is one of the important tracers of the diffuse neutral interstellar medium. Radio astronomical observations of this transition, using either a single dish telescope or an array…
We investigate the intermittency of magnetic turbulence as measured in Reversed Field Pinch plasmas. We show that the Probability Distribution Functions of magnetic field differences are not scale invariant, that is the wings of these…
The status of our current understanding of angular momentum transport in accretion disks is reviewed. The last decade has seen a dramatic increase both in the recognition of key physical processes and in our ability to carry through direct…
Understanding the mechanism that drives accretion has been the primary challenge in accretion disk theory. Turbulence provides a natural means of dissipation and the removal of angular momentum, but firmly establishing its presence in disks…
This paper describes some interesting properties of waves in, and oscillations of, the interstellar medium in the direction normal to the plane of the Galaxy. Our purpose is to examine possible reasons for four observed phenomena: the…