相关论文: Lagrangian statistics of a shock-driven turbulent …
Magnetic fields on the order of 100 $\mu$G observed in young supernova remnants cannot be amplified by shock compression alone. To investigate the amplification caused by turbulent dynamo, we perform three-dimensional MHD simulations of the…
In this paper we further advance the study of magnetic field amplification in the interstellar medium that was started in Balsara et al (2004, Paper I). We show that the flux growth rate is comparable to the rate of magnetic energy growth…
We perform two-dimensional relativistic magnetohydrodynamic simulations of a mildly relativistic shock propagating through an inhomogeneous medium. We show that the postshock region becomes turbulent owing to preshock density inhomogeneity,…
We have investigated via two-dimensional relativistic MHD simulations the long-term evolution of turbulence created by a relativistic shock propagating through an inhomogeneous medium. In the postshock region, magnetic field is strongly…
Based on the new findings on the turbulent dynamo in \citet{XL16}, we examine the magnetic field amplification in the context of supernova remnants. Due to the strong ion-neutral collisional damping in the weakly-ionized interstellar…
We derive analytically the vorticity generated downstream of a two-dimensional rippled hydromagnetic shock neglecting fluid viscosity and resistivity. The growth of the turbulent component of the downstream magnetic field is driven by the…
Turbulent dynamo field amplification has often been invoked to explain the strong field strengths in thin rims in supernova shocks ($\sim 100 \, \mu$G) and in radio relics in galaxy clusters ($\sim \mu$G). We present high resolution MHD…
Magnetic field strengths inferred for relativistic outflows including gamma-ray bursts (GRB) and active galactic nuclei (AGN) are larger than naively expected by orders of magnitude. We present three-dimensional relativistic…
The universe is permeated by magnetic fields, with strengths ranging from a femtogauss in the voids between the filaments of galaxy clusters to several teragauss in black holes and neutron stars. The standard model behind cosmological…
We have performed extensive two-dimensional magnetohydrodynamic simulations to study the amplification of magnetic fields when a supernova blast wave propagates into a turbulent interstellar plasma. The blast wave is driven by injecting…
Magnetic fields have been included in cosmological simulations of galaxy formation only recently, due to advances in numerical techniques and a better understanding of the galaxy formation physics. In this paper, we develop a new subgrid…
The small-scale turbulent dynamo is a key mechanism for amplifying galactic magnetic fields, yet the resulting field morphology remains poorly understood. Using 3D driven turbulence simulations across a range of compressibilities,…
Relativistic astrophysical phenomena such as gamma-ray bursts (GRBs) and active galactic nuclei often require long-lived strong magnetic field. Here, we report on three-dimensional special-relativistic magnetohydrodynamic (MHD) simulations…
We study the long term evolution of magnetic fields generated by a collisionless relativistic $e^+e^-$ shock which is initially unmagnetized. Our 2D particle-in-cell numerical simulations show that downstream of such a Weibel-mediated…
We describe the initial implementation of magnetohydrodynamics (MHD) in our astrophysical simulation code \genasis. Then, we present MHD simulations exploring the capacity of the stationary accretion shock instability (SASI) to generate…
This research was motivated by the recent observations indicating very strong magnetic fields at some supernova remnant shocks, which suggests in-situ generation of magnetic turbulence. The dissertation presents a numerical model of…
Direct numerical simulations of turbulent Hall dynamos are presented. The evolution of an initially weak and small scale magnetic field in a system maintained in a stationary turbulent regime by a stirring force at a macroscopic scale is…
Magnetic fields are ubiquitous in the Universe. Extragalactic disks, halos and clusters have consistently been shown, via diffuse radio-synchrotron emission and Faraday rotation measurements, to exhibit magnetic field strengths ranging from…
The presence of magnetic fields in many astrophysical objects is due to dynamo action, whereby a part of the kinetic energy is converted into magnetic energy. A turbulent dynamo that produces magnetic field structures on the same scale as…
Magnetic fields are widely observed in the Universe in virtually all astrophysical objects, from individual stars to entire galaxies, even in the intergalactic medium, but their specific generation has long been debated. Due to the…