Related papers: Disk Formation in Magnetized Dense Cores with Turb…
Migration of protoplanets in their gaseous host disks may be largely responsible for the observed orbital distribution of extrasolar planets. Recent simulations have shown that the magnetorotational turbulence thought to drive accretion in…
We discuss star formation in the turbulent interstellar medium. We argue that morphological appearance and dynamical evolution of the gas is primarily determined by supersonic turbulence, and that stars form via a process we call…
Activity of the nuclei of galaxies and stellar mass systems involving disk accretion to black holes is thought to be due to (1) a small-scale turbulent magnetic field in the disk (due to the magneto-rotational instability or MRI) which…
In their early stages, protoplanetary discs are sufficiently massive to undergo gravitational instability (GI). This instability is thought to be involved in mass accretion, planet formation via gas fragmentation, the generation of spiral…
In this paper, we provide a more accurate description of the evolution of the magnetic flux redistribution during prestellar core collapse by including resistive terms in the magnetohydrodynamics (MHD) equations. We focus more particularly…
Although protostars and disks are often studied separately owing to numerical and observational challenges, breakthroughs in recent years have highlighted the need to study both objects in concert. The role of magnetic fields in this regard…
Protostars are born in magnetized environments. As a consequence, the formation of protostellar disks can be suppressed by the magnetic field efficiently removing angular momentum of the infalling material. Non-ideal MHD effects are…
We employ the three-dimensional magnetohydrodynamic simulation including ambipolar diffusion to study the gravitationally-driven fragmentation of subcritical molecular clouds, in which the gravitational fragmentation is stabilized as long…
In this paper we present the global baroclinic instability as a source for vigorous turbulence leading to angular momentum transport in Keplerian accretion disks. We show by analytical considerations and three-dimensional radiation hydro…
The processes of planet formation and migration depend intimately on the interaction between planetesimals and the gaseous disks in which they form. The formation of gaps in the disk can severely limit the mass of the planet and its…
Despite extensive study, the mechanisms by which Be star disks acquire high densities and angular momentum while displaying variability on many time scales are still far from clear. In this paper, we discuss how magnetic torquing may help…
We perform a comparative numerical hydrodynamics study of embedded protostellar disks formed as a result of the gravitational collapse of cloud cores of distinct mass (M_cl=0.2--1.7 M_sun) and ratio of rotational to gravitational energy…
Observations indicate that dense molecular filamentary clouds are sites of star formation. The filament width determines the most unstable scale for self-gravitational fragmentation and influences the stellar mass. Therefore, constraining…
We demonstrate that the formation of collapsing cores in subcritical clouds is accelerated by nonlinear flows, by performing three-dimensional non-ideal MHD simulations. An initial random supersonic (and trans-Alfvenic) turbulent-like flow…
Recent advances in our understanding of massive star formation have made clear the important role of protostellar disks in mediating accretion. Here we describe a simple, semi-analytic model for young, deeply embedded, massive accretion…
Protoplanetary discs exhibit a diversity of gaps and rings of dust material, believed to be a manifestation of pressure maxima commonly associated with an ongoing planet formation and several other physical processes. Hydrodynamic disc…
In recent years, it has been demonstrated that massive stars see their infant circumstellar medium shaped into a large, irradiated, gravitationally unstable accretion disc during their early formation phase. Such discs constitute the gas…
Disc fragmentation provides an important mechanism for producing low mass stars in prestellar cores. Here, we describe Smoothed Particle Hydrodynamics simulations which show how populations of prestellar cores evolve into stars. We find the…
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…
The accretion phase of star formation is investigated in magnetically-dominated clouds that have an initial subcritical mass-to-flux ratio. We employ nonideal magnetohydrodynamic simulations that include ambipolar diffusion and ohmic…