Related papers: Radiative, magnetic and numerical feedbacks on sma…
We studied roles of a turbulent resistivity in the core-collapse of a strongly magnetized massive star, carrying out 2D-resistive-MHD simulations. The three cases with different initial strengths of magnetic field and rotation are…
Spectropolarimetry of core collapse supernovae has shown that they are asymmetric and often, but not universally, bi-polar. The Type IIb SN1993J and similar events showed large scatter in the Stokes parameter plane. Observational programs…
Are the kG-strength magnetic fields observed in young stars a fossil field left over from their formation or are they generated by a dynamo? Our previous numerical study concluded that magnetic fields must originate by a dynamo process.…
We obtain self-similar solutions that describe the gravitational collapse of nonrotating, isothermal, magnetic molecular cloud cores. We use simplifying assumptions but explicitly include the induction equation, and the semianalytic…
(Abridged) We explore, by means of a large ensemble of SPH simulations, how the level of turbulence affects the collapse and fragmentation of a star-forming core. All our simulated cores have the same, except that we vary (a) the initial…
We study the influence of constant magnetic field combined with a field induced by the external thermal environment on the atomic decay rates. The importance of radiative corrections, including magnetic interaction, is demonstrated for…
Linear analysis of the formation of protostellar cores in planar magnetic interstellar clouds yields information about length scales involved in star formation. Combining these length scales with various distributions of other environmental…
Massive stars ($M > 8$ \msun) typically form in parsec-scale molecular clumps that collapse and fragment, leading to the birth of a cluster of stellar objects. We investigate the role of magnetic fields in this process through dust…
Magnetic fields are usually considered dynamically important in star formation when the dimensionless mass-to-flux ratio is close to, or less than, unity (lambda<~1). We show that, in disk formation, the requirement is far less stringent.…
A dynamical model based on the two-fluid dynamical equations with energy generation and loss is obtained and used to investigate the self-generated magnetic fields in high-temperature dense plasmas such as the solar core. The…
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…
The theory of how low mass stars form from the collapse of a dense molecular cloud core has been well-established for decades. Thanks to significant progress in computing and numerical modelling, more physical models have been developed and…
The transport of angular momentum by magnetic fields is a crucial physical process in formation and evolution of stars and disks. Because the ionization degree in star forming clouds is extremely low, non-ideal magnetohydrodynamic (MHD)…
The magnetorotational instability (MRI) is key physics in accretion disks and is widely considered to play some role in massive-star core collapse. Models of rotating massive stars naturally develop very strong shear at composition…
We investigate the change in stellar magnetic topology across the fully-convective boundary and its effects on coronal properties. We consider both the magnitude of the open flux that influences angular momentum loss in the stellar wind and…
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…
We investigate the formation and evolution of a first core, protostar, and circumstellar disc with a three-dimensional non-ideal (including both Ohmic and ambipolar diffusion) radiation magnetohydrodynamics simulation. We found that the…
In order to shed light on the main physical processes controlling fragmentation of massive dense cores, we present a uniform study of the density structure of 19 massive dense cores, selected to be at similar evolutionary stages, for which…
Abridged: We use three-dimensional SPH simulations to investigate the collapse of low-mass prestellar cores and the formation and early evolution of protostellar discs. The initial conditions are slightly supercritical Bonnor-Ebert spheres…
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…