相关论文: Numerical Studies of the Kelvin-Hemholtz Instabili…
We study the linear stability of a planar interface separating two fluids in relative motion, focusing on conditions appropriate for the boundaries of relativistic jets. The jet is magnetically dominated, whereas the ambient wind is…
Extreme-ultraviolet and X-ray jets occur frequently in magnetically open coronal holes on the Sun, especially at high solar latitudes. Some of these jets are observed by white-light coronagraphs as they propagate through the outer corona…
We report on a three-dimensional MHD numerical experiment of a small scale coronal mass ejection (CME) -like eruption propagating though a non-magnetized solar atmosphere. We find that the Kelvin-Helmholtz instability (KHI) develops at…
The effect of optically thin radiative cooling on the Kelvin-Helmholtz instability of three dimensional jets is investigated via linear stability theory and nonlinear hydrodynamical simulation. Two different cooling functions are…
Using a new numerical code we have carried out two-dimensional simulations of the nonlinear evolution of unstable sheared magnetohydrodynamic flows. We considered two cases: a strong magnetic field (Alfven Mach number, M_a = 2.5) and a weak…
Fast magnetic reconnection events can play an important role in accretion disk systems. A potential model to explain the non-thermal very-high-energy (VHE) emission (from GeV to TeV) observed in black-hole binaries (BHBs) and Active Galatic…
We have performed 2.5D and 3D simulations of conical jets driven by the rotation of an ordered, large-scale magnetic field in a stratified atmosphere. The simulations cover about three orders of magnitude in distance to capture the…
Coronal-hole jets occur ubiquitously in solar coronal holes, at EUV and X-ray bright points associated with intrusions of minority magnetic polarity. The embedded-bipole model for these jets posits that they are driven by explosive, fast…
The ubiquitous relativistic jet phenomena associated with black holes play a major role in high and very-high-energy (VHE) astrophysics. In particular, observations have demonstrated that blazars show VHE emission with time-variability from…
We investigate the launching and stability of extragalactic jets through nonlinear magnetohydrodynamic (MHD) simulation and linear eigenmode analysis. In the simulations of jet evolution, a small-scale equilibrium magnetic arcade is twisted…
The long term magnetohydrodynamic stability of magnetized transonic/supersonic jets is numerically investigated using a spatial approach. We focus on two-dimensional linearly-unstable slab configurations where the jet is embedded in a…
In the present paper, we examine the convergence behavior and inter-code reliability of astrophysical jet simulations in axial symmetry. We consider both, pure hydrodynamic jets and jets with a dynamically significant magnetic field. The…
The Kelvin-Helmholtz instability is a ubiquitous physical process in ordinary fluids and plasmas, frequently observed also in space environments. In this paper, kinetic effects at proton scales in the nonlinear and turbulent stage of the…
The amplitude of jet distortions and accompanying pressure and velocity fluctuations resulting from Kelvin-Helmholtz instability of three dimensional relativistic jets are explored. The effect of instability on jets as they accelerate from…
Three extreme-ultraviolet (EUV) jets recurred in about one hour on 2010 September 17 in the following magnetic polarity of active region 11106. The EUV jets were observed by the Atmospheric Imaging Assembly (AIA) on board the Solar Dynamics…
Recent observations show cool, oscillating prominence threads fading when observed in cool spectral lines and appearing in warm spectral lines. A proposed mechanism to explain this evolution is that the threads were heated by turbulence…
The Kelvin-Helmholtz instability is well-known in classical hydrodynamics, where it explains the sudden emergence of interfacial surface waves as a function of the velocity of flow parallel to the interface. It can be carried over to the…
Jets powered by active galactic nuclei appear impressively stable compared with their terrestrial and laboratory counterparts-they can be traced from their origin to distances exceeding their injection radius by up to a billion times.…
The linear MHD Kelvin-Helmholtz instability (KHI) in an anisotropic plasma concerning the direction of an external magnetic field is examined in detail. For this purpose, the MHD equations are used to describe the motion of plasma as a…
Radio and optical images of the M87 jet show bright filaments, twisted into an apparent double helix, extending from HST-1 to knot A. Proper motions within the jet suggest a decelerating jet flow passing through a slower, accelerating wave…