Magnetohydrodynamic Models of the Bipolar Knotty Jet in Henize 2‐90

2004 ◽  
Vol 606 (1) ◽  
pp. 483-496 ◽  
Author(s):  
Chin‐Fei Lee ◽  
Raghvendra Sahai
Keyword(s):  
Magnetohydrodynamic Models

scholarly journals A class of three-dimensional gyroviscous magnetohydrodynamic models

2020 ◽  
Vol 86 (5) ◽  
Author(s):  
Manasvi Lingam ◽  
Philip J. Morrison ◽  
Alexander Wurm
Keyword(s):  
First Principles ◽  
Three Dimensional ◽  
Action Principle ◽  
Wide Range ◽  
Magnetohydrodynamic Models

A Hamiltonian and action principle formalism for deriving three-dimensional gyroviscous magnetohydrodynamic models is presented. The uniqueness of the approach in constructing the gyroviscous tensor from first principles and its ability to explain the origin of the gyromap and the gyroviscous terms are highlighted. The procedure allows for the specification of free functions, which can be used to generate a wide range of gyroviscous models. Through the process of reduction, the noncanonical Hamiltonian bracket is obtained and briefly analysed.

scholarly journals Plasma environment of Titan: a 3-D hybrid simulation study

2006 ◽  
Vol 24 (3) ◽  
pp. 1113-1135 ◽  
Author(s):  
S. Simon ◽  
A. Bößwetter ◽  
T. Bagdonat ◽  
U. Motschmann ◽  
K.-H. Glassmeier
Keyword(s):  
Plasma Flow ◽  
Molecular Nitrogen ◽  
Hybrid Simulation ◽  
Spherical Geometry ◽  
Magnetospheric Plasma ◽  
Simulation Code ◽  
Plasma Environment ◽  
Ion Production ◽  
Solar Uv ◽  
Magnetohydrodynamic Models

Abstract. Titan possesses a dense atmosphere, consisting mainly of molecular nitrogen. Titan's orbit is located within the Saturnian magnetosphere most of the time, where the corotating plasma flow is super-Alfvénic, yet subsonic and submagnetosonic. Since Titan does not possess a significant intrinsic magnetic field, the incident plasma interacts directly with the atmosphere and ionosphere. Due to the characteristic length scales of the interaction region being comparable to the ion gyroradii in the vicinity of Titan, magnetohydrodynamic models can only offer a rough description of Titan's interaction with the corotating magnetospheric plasma flow. For this reason, Titan's plasma environment has been studied by using a 3-D hybrid simulation code, treating the electrons as a massless, charge-neutralizing fluid, whereas a completely kinetic approach is used to cover ion dynamics. The calculations are performed on a curvilinear simulation grid which is adapted to the spherical geometry of the obstacle. In the model, Titan's dayside ionosphere is mainly generated by solar UV radiation; hence, the local ion production rate depends on the solar zenith angle. Because the Titan interaction features the possibility of having the densest ionosphere located on a face not aligned with the ram flow of the magnetospheric plasma, a variety of different scenarios can be studied. The simulations show the formation of a strong magnetic draping pattern and an extended pick-up region, being highly asymmetric with respect to the direction of the convective electric field. In general, the mechanism giving rise to these structures exhibits similarities to the interaction of the ionospheres of Mars and Venus with the supersonic solar wind. The simulation results are in agreement with data from recent Cassini flybys.

scholarly journals Dusty magnetohydrodynamics in star-forming regions

2010 ◽  
Vol 76 (3-4) ◽  
pp. 569-578
Author(s):  
S. VAN LOO ◽  
S. A. E. G. FALLE ◽  
T. W. HARTQUIST ◽  
O. HAVNES ◽  
G. E. MORFILL
Keyword(s):  
Star Formation ◽  
Large Scale ◽  
Number Density ◽  
Star Forming ◽  
Star Forming Regions ◽  
Neutral Gas ◽  
Gas Phase Ions ◽  
Fractional Ionization ◽  
Magnetohydrodynamic Models ◽  
The Magnetic Field

AbstractStar formation occurs in dark molecular regions where the number density of hydrogen nuclei nH exceeds 104 cm−3 and the fractional ionization is 10−7 or less. Dust grains with sizes ranging up to tenths of microns and perhaps down to tens of nanometers contain just less than 1% of the mass. Recombination on grains is important for the removal of gas-phase ions, which are produced by cosmic rays penetrating the dark regions. Collisions of neutrals with charged grains contribute significantly to the coupling of the magnetic field to the neutral gas. Consequently, the dynamics of the grains must be included in the magnetohydrodynamic models of large-scale collapse, the evolution of waves and the structures of shocks important in star formation.

scholarly journals The Environment of the Young Earth in the Perspective of An Young Sun

2016 ◽  
Vol 12 (S328) ◽  
pp. 315-328
Author(s):  
Vladimir S. Airapetian
Keyword(s):  
Space Weather ◽  
Solar Flares ◽  
Geomagnetic Storms ◽  
Lower Atmosphere ◽  
Early Earth ◽  
Uv Emission ◽  
Weather Events ◽  
Active Stars ◽  
Magnetohydrodynamic Models ◽  
The Impact

AbstractOur Sun, a magnetically mild star, exhibits space weather in the form of magnetically driven solar explosive events (SEE) including solar flares, coronal mass ejections and energetic particle events. We use Kepler data and reconstruction of X-ray and UV emission from young solar-like stars to recover the frequency and energy fluxes from extreme events from active stars including the young Sun. Extreme SEEs from a magnetically active young Sun could significantly perturb the young Earth's magnetosphere, cause strong geomagnetic storms, initiate escape and introduce chemical changes in its lower atmosphere. I present our recent simulations results based on multi-dimensional multi-fluid hydrodynamic and magnetohydrodynamic models of interactions of extreme CME and SEP events with magnetospheres and lower atmospheres of early Earth and exoplanets around active stars. We also discuss the implications of the impact of these effects on evolving habitability conditions of the early Earth and prebiotic chemistry introduced by space weather events at the early phase of evolution of our Sun.

scholarly journals Resistive jet simulations extending radially self-similar magnetohydrodynamic models

2008 ◽  
Vol 389 (3) ◽  
pp. 1022-1032 ◽  
Author(s):  
M. Čemeljić ◽  
J. Gracia ◽  
N. Vlahakis ◽  
K. Tsinganos
Keyword(s):  
Self Similar ◽  
Magnetohydrodynamic Models

Helmet Streamers Gone Unstable: Two‐Fluid Magnetohydrodynamic Models of the Solar Corona

2004 ◽  
Vol 603 (1) ◽  
pp. 307-321 ◽  
Author(s):  
Eirik Endeve ◽  
Thomas E. Holzer ◽  
Egil Leer
Keyword(s):  
Solar Corona ◽  
Magnetohydrodynamic Models ◽  
Two Fluid
Sign in / Sign up

Export Citation Format

Share Document