Related papers: Angular Momenta, Magnetization, and Accretion of P…
Context. The influence of magnetic fields on stellar core collapse and explosion is not well explored. It depends on the possibility to amplify the pre-collapse fields. Without rotation this can happen by compression, convection, the…
Most analytic work to date on protostellar disks has focused on those in isolation from their environments. However, observations are now beginning to probe the earliest, most embedded phases of star formation, during which disks are…
The collapse and fragmentation of initially prolate and oblate, magnetic molecular clouds is calculated in three dimensions with a gravitational, radiative hydrodynamics code. The code includes magnetic field effects in an approximate…
We find that convective regions of collapsing massive stellar cores possess sufficient stochastic angular momentum to form intermittent accretion disks around the newly born neutron star (NS) or black hole (BH), as required by the…
We present the results of fully 3-D hydrodynamic simulations of the gravitational collapse of isolated, turbulent molecular cloud cores. Starting from initial states of hydrostatic equilibrium, we follow the collapse of both singular and…
We present self-similar solutions that describe the gravitational collapse of rotating, isothermal, magnetic molecular-cloud cores, relevant to the formation of rotationally supported protostellar disks. This work focuses on the evolution…
We use axisymmetric magnetohydrodynamic (MHD) simulations to investigate the launching and collimation of jets emerging from the disk-magnetosphere boundary of accreting magnetized stars. Our analysis shows that the matter flows into the…
We investigate the formation of protostellar clusters during the collapse of dense molecular cloud cores with a focus on the evolution of potential and kinetic energy, the degree of substructure, and the early phase of mass segregation. Our…
The pre-stellar cores in which low mass stars form are generally well magnetized. Our simulations show that early protostellar discs are massive and experience strong magnetic torques in the form of magnetic braking and protostellar…
We study the general-relativistic dynamics of matter being accreted onto and ejected by a magnetised and nonrotating neutron star. The dynamics is followed in the framework of fully general relativistic magnetohydrodynamics (GRMHD) within…
We present an idealized, spherical model of the evolution of a magnetized molecular cloud due to ambipolar diffusion. This model allows us to follow the quasi-static evolution of the cloud's core prior to collapse and the subsequent…
Collapse of the rotating magnetized molecular cloud core is studied with the axisymmetric magnetohydrodynamical (MHD) simulations. Due to the change of the equation of state of the interstellar gas, the molecular cloud cores experience…
Throughout the Hubble time, gas makes its way from the intergalactic medium into galaxies fuelling their star formation and promoting their growth. One of the key properties of the accreting gas is its angular momentum, which has profound…
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…
Resolution studies of test problems set baselines and help define minimum resolution requirements, however, resolution studies must also be performed on scientific simulations to determine the effect of resolution on the specific scientific…
Grid-based magnetohydrodynamic (MHD) simulations have proven invaluable for the study of astrophysical accretion disks. However, the fact that angular momentum transport in disks is mediated by MHD turbulence (with structure down to very…
In the context of star and planet formation, understanding the formation of disks is of fundamental importance. Previous studies found that the magnetic field has a very strong impact on the collapse of a prestellar cloud, particularly in…
While it is generally accepted that the magnetic field and its non-ideal effects play important roles during the stellar formation, simple models of pure hydrodynamics and angular momentum conservation are still widely employed in the…
In star formation, magnetic fields act as a cosmic angular momentum extractor that increases mass accretion rates onto protostars and in the process, creates spectacular outflows. However, recently it has been argued that this magnetic…
We review the numerical techniques for ideal and non-ideal magneto-hydrodynamics (MHD) used in the context of star formation simulations. We outline the specific challenges offered by modeling star forming environments, which are dominated…