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Related papers: Parametric instability in dark molecular clouds

200 papers

A full particle simulation study is carried out for studying microinstabilities generated at the shock front of perpendicular collisionless shocks. The structure and dynamics of shock waves are determined by Alfven Mach number and plasma…

Plasma Physics · Physics 2015-06-04 Takayuki Umeda , Yoshitaka Kidani , Shuichi Matsukiyo , Ryo Yamazaki

The paper studies the drift instability in Kappa-distributed inhomogeneous plasmas. Weak inhomogeneity and local approximation are assumed. The linear dispersion relation is expressed in a novel integral representation that involves the…

Plasma Physics · Physics 2023-12-27 Ran Guo

We performed one-dimensional hydrodynamic simulations with detailed cooling, heating and chemical processes to examine the thermal stability of shocked gas in cold neutral medium (CNM) and molecular clouds. We find that both CNM and…

Solar and Stellar Astrophysics · Physics 2015-06-16 Takuhiro Aota , Tsuyoshi Inoue , Yuri Aikawa

Spatiotemporal properties of two-dimensional (2D) Hall-magnetohydrodynamic turbulence at intermediate plasma $\beta=2$ are studied by means of Fast Iterative Filtering, a new technique for the decomposition of nonstationary nonlinear…

We investigate the interaction of a plane, linearly polarized, Alfvenic pulse with a one-dimensional, perpendicular to the magnetic field, plasma density inhomogeneity in the strongly nonlinear regime. Our numerical study of the full MHD…

Astrophysics · Physics 2009-11-07 D. Tsiklauri , V. M. Nakariakov , T. D. Arber

We study the linear evolution of small perturbations in self-gravitating fluid systems in two spatial dimensions; we consider both cylindrical and cartesian (i.e., slab) geometries. The treatment is general, but the application is to…

Astrophysics · Physics 2009-10-28 Curtis S. Gehman , Fred C. Adams , Marco Fatuzzo , Richard Watkins

Inhomogeneous plasmas filaments instabilities are investigated by using the techniques of classical differential geometry of curves where Frenet torsion and curvature describe completely the motion of curves. In our case the Frenet frame…

Mathematical Physics · Physics 2007-05-23 Garcia de Andrade

The gravitational instability of a filamentary molecular cloud in non-ideal magnetohydrodynamics is investigated. The filament is assumed to be in hydrostatic equilibrium. We add the effect of ambipolar diffusion to the filament which is…

Astrophysics of Galaxies · Physics 2016-12-21 Mohammad Hosseinirad , Kazem Naficy , Shahram Abbassi , Mahmood Roshan

We investigate dispersive and kinetic effects on the evolution of a two-dimensional kinked Alfv\'en wave packet by comparing results from MHD, Hall-MHD and hybrid simulations of a low-$\beta$ plasma. We find that the Hall term determines…

Solar and Stellar Astrophysics · Physics 2026-05-07 Anna Tenerani , Carlos González , Nikos Sioulas , Chen Shi , Marco Velli

Microscopic instability and macroscopic flow pattern resulting from colliding plasmas are studied analytically in support of laboratory experiments. The plasma flows are assumed to stream radially from two separate centers. In a…

Plasma Physics · Physics 2018-11-13 Mikhail Malkov , Vladimir Sotnikov

There are several astrophysical situations where one needs to study the dynamics of magnetic flux in partially ionized turbulent plasmas. In a partially ionized plasma the magnetic induction is subjected to the ambipolar diffusion and the…

Astrophysics · Physics 2009-11-13 V. Krishan , R. T. Gangadhara

Turbulent high-energy astrophysical systems often feature asymmetric energy injection: for instance, Alfven waves propagating from an accretion disk into its corona. Such systems are "imbalanced": the energy fluxes parallel and…

High Energy Astrophysical Phenomena · Physics 2021-12-22 Amelia Hankla , Vladimir Zhdankin , Gregory Werner , Dmitri Uzdensky , Mitchell Begelman

Using self-consistent magnetohydrodynamic (MHD) simulations, we explore the hypothesis that nonlinear MHD waves dominate the internal dynamics of galactic molecular clouds. We employ an isothermal equation of state and allow for…

Astrophysics · Physics 2016-08-30 Charles F. Gammie , Eve C. Ostriker

The large-scale dynamics of plasmas is well described within the framework of magnetohydrodynamics (MHD). However, whenever the ion density of the plasma becomes sufficiently low, the Hall effect is likely to become important. The role of…

Solar and Stellar Astrophysics · Physics 2012-07-04 Cecilia Bejarano , Daniel Gómez , Axel Brandenburg

Turbulence in astrophysical and space plasmas is dominated by the nonlinear interaction of counterpropagating Alfven waves. Most Alfven wave turbulence theories have been based on ideal plasma models, such as incompressible MHD, for Alfven…

In magnetized plasmas, a radial gradient of parallel velocity, where parallel refers to the direction of magnetic field, can destabilise an electrostatic mode called Parallel Velocity Gradient (PVG). The theory of PVG has been mainly…

Plasma Physics · Physics 2025-05-07 Jeanne Bourgeois , Maxime Lesur , Guillermo Cuerva Lazaro , Yusuke Kosuga

The relationship between a decaying strong turbulence and kinetic instabilities in a slowly expanding plasma is investigated using two-dimensional (2-D) hybrid expanding box simulations. We impose an initial ambient magnetic field…

The Hall effect arises in a plasma when electrons are able to drift with the magnetic field but ions cannot. In a fully-ionized plasma this occurs for frequencies between the ion and electron cyclotron frequencies because of the larger ion…

Astrophysics · Physics 2009-11-13 B. P. Pandey , Mark Wardle

It is demonstrated that low frequency shear modes in a strongly coupled, inhomogeneous, dusty plasma can grow on account of an instability involving the dynamical charge fluctuations of the dust grains. The instability is driven by the…

Plasma Physics · Physics 2009-11-07 Amruta Mishra , P. K. Kaw , A. Sen

Weakly collisional space plasmas are rarely in local thermal equilibrium and often exhibit non-Maxwellian electron and ion velocity distributions that lead to the growth of microinstabilities, that is, enhanced electric and magnetic fields…