相关论文: Magnetic field generation by the stationary accret…

The Standing Accretion Shock Instability (SASI) is commonly believed to be responsible for large amplitude dipolar oscillations of the stalled shock during core collapse, potentially leading to an asymmetric supernovae explosion. The degree…

In the collapsing core of massive stars, the standing accretion shock instability (SASI) can drive spiral modes that efficiently redistribute angular momentum. This process can impart a spin to the forming neutron star even when the…

We present a model for the seeding and evolution of magnetic fields in galaxies by supernovae (SN). SN explosions during galaxy assembly provide seed fields, which are subsequently amplified by compression, shear flows and random motions.…

Supernova Remnants (SNRs) shocks are believed to accelerate charged particles and to generate strong turbulence in the post-shock flow. From high-energy observations in the past decade, a magnetic field at SNR shocks largely exceeding the…

We investigate an electromagnetic instability in two-dimensional materials arising from an anisotropy of the Fermi surface, utilizing a kinetic model accounting for the effects of the values of temperature, chemical potential and anisotropy…

We present a new scenario for magnetic field amplification where an electrically conducting fluid is confined in a differentially rotating, spherical shell with thin aspect-ratio. When the angular momentum sufficiently decreases outwards,…

The possibility of the existence of quasi-stationary electromagnetic fields in plasma supported by their own self-consistent current follows from Maxwell's equations with field sources. These equations also give rise to a wave equation for…

We investigate the magnetic field which is generated by turbulent motions of a weakly ionized gas. Galactic molecular clouds give us an example of such a medium. As in the Kazantsev-Kraichnan model we assume a medium to be homogeneous and a…

The current understanding of astrophysical magnetic fields is reviewed, focusing on their generation and maintenance by turbulence. In the astrophysical context this generation is usually explained by a self-excited dynamo, which involves…

The filamentation instability triggered when two counter streaming plasma shells overlap appears to be the main mechanism by which collisionless shocks are generated. It has been known for long that a flow aligned magnetic field can…

Here we present the results from two sets of simulations, in two and three spatial dimensions. In two dimensions, the simulations include multifrequency flux-limited diffusion neutrino transport in the "ray-by-ray-plus" approximation,…

Building on earlier work, we develop an equation-of-motion method for calculating magnetic seed fields generated from currents arising from charged W fields in bubble collisions during a first-order primordial electroweak phase transition…

Without amplification, magnetic fields in expanding ejecta of young supernova remnants (SNRs) will be orders of magnitude below those required to shock accelerate thermal electrons, or ions, to relativistic energies or to produce radio…

The success of the neutrino mechanism of core-collapse supernovae relies on the supporting action of two hydrodynamic instabilities: neutrino-driven convection and the Standing Accretion Shock Instability (SASI). Depending on the structure…

We performed the first numerical simulations of magnetorotational instability from a sub-magnetar-class seed magnetic field in core collapse supernovae. As a result of axisymmetric ideal MHD simulations, we found that the magnetic field is…

An axisymmetric magnetic field is applied to a spherical, turbulent flow of liquid sodium. An induced magnetic dipole moment is measured which cannot be generated by the interaction of the axisymmetric mean flow with the applied field,…

We model strong forward shocks in young supernova remnants with efficient particle acceleration where a nonresonant instability driven by the cosmic ray current amplifies magnetic turbulence in the shock precursor. Particle injection,…

We examine the stability of standing, spherical accretion shocks. Accretion shocks arise in core collapse supernovae (the focus of this paper), star formation, and accreting white dwarfs and neutron stars. We present a simple analytic model…

We present a new mechanism for oscillatory or random reversals of the magnetic field that occur from a stationary dynamo state. The basic ingredient is the existence of two nearly critical dynamo eigenmodes, a stable and an unstable one,…

We investigate the generation of magnetic fields above black hole accretion discs due to the non-zero curl of the disc radiation field. By self consistently computing the components of the radiation flux and their curl, we show that the…