Related papers: Disk Formation in Magnetized Clouds Enabled by the…
We discuss the effects of the magnetic field observed in molecular clouds on the process of star formation, concentrating on the phase of gravitational collapse of low-mass dense cores, cradles of sunlike stars. We summarize recent analytic…
We demonstrate the formation of gravitationally unstable discs in magnetized molecular cloud cores with initial mass-to-flux ratios of 5 times the critical value, effectively solving the magnetic braking catastrophe. We model the…
Non-ideal magnetohydrodynamic (MHD) processes -- namely Ohmic resistivity, ambipolar diffusion and the Hall effect -- modify the early stages of the star formation process and the surrounding environment. Collectively, they have been shown…
We use magnetic collapse models to place some constraints on the formation and angular momentum evolution of circumstellar disks which are embedded in magnetized cloud cores. Previous models have shown that the early evolution of a…
Stars form from the gravitational collapse of turbulent, magnetized molecular cloud cores. Our non-ideal MHD simulations reveal that the intrinsically anisotropic magnetic resistance to gravity during the core collapse naturally generates…
Stars form in dense cores of molecular clouds that are observed to be significantly magnetized. In the simplest case of a laminar (non-turbulent) core with the magnetic field aligned with the rotation axis, both analytic considerations and…
We present results from the first radiation non-ideal magnetohydrodynamics (MHD) simulations of low-mass star cluster formation that resolve the fragmentation process down to the opacity limit. We model 50~M$_\odot$ turbulent clouds…
The formation of circumstellar discs is a critical step in the formation of stars and planets. Magnetic fields can strongly affect the evolution of angular momentum during prestellar core collapse, potentially leading to the failure of…
A non-ideal MHD collapse calculation employing the axisymmetric thin-disk approximation is used to resolve cloud core collapse down to the scales of the second (stellar) core. Rotation and a magnetic braking torque are included in the…
Theoretical studies of collapsing clouds have found that even a relatively weak magnetic field (B) may prevent the formation of disks and their fragmentation. However, most previous studies have been limited to cases where B and the…
We present simulations of collapsing 100 M_\sun mass cores in the context of massive star formation. The effect of variable initial rotational and magnetic energies on the formation of massive stars is studied in detail. We focus on…
The global evolution of protoplanetary disks (PPDs) has recently been shown to be largely controlled by the amount of poloidal magnetic flux threading the disk, which is further controlled by the poorly understood process of magnetic flux…
We investigate and discuss protostellar discs in terms of where the various non-ideal magnetohydrodynamics (MHD) processes are important. We find that the traditional picture of a magnetised disc (where Ohmic resistivity is dominant near…
Disks are essential to the formation of both stars and planets, but how they form in magnetized molecular cloud cores remains debated. This work focuses on how the disk formation is affected by turbulence and ambipolar diffusion (AD), both…
Non-ideal magnetohydrodynamics (MHD) is the dominant process. We investigate the effect of magnetic fields (ideal and non-ideal) and turbulence (sub- and transsonic) on the formation of protostars by following the gravitational collapse of…
The breakdown of flux-freezing in molecular clouds and protostellar discs is usually approximated by ambipolar diffusion at low densities or by resistive diffusion at high densities. Here I discuss an intermediate regime in which the Hall…
In the present-day universe, magnetic fields play such essential roles in star formation as angular momentum transport and outflow driving, which control circumstellar disc formation/fragmentation and also the star formation efficiency.…
Are magnetic fields important in primordial star formation? Assuming that star formation occurs via an accretion disk that is turbulent, initially because of local gravitational instability, we calculate the disk structure for realistic…
We examine the effect of magnetic fields on star cluster formation by performing simulations following the self-gravitating collapse of a turbulent molecular cloud to form stars in ideal MHD. The collapse of the cloud is computed for global…
We have performed magnetohydrodynamic (MHD) simulations of the collapse and fragmentation of molecular cloud cores using a new algorithm for MHD within the smoothed particle hydrodynamics (SPH) method, that enforces the zero magnetic…