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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…

The solar wind is a magnetized and turbulent plasma. Its turbulence is often dominated by Alfv\'enic fluctuations and often deemed as nearly incompressible far away from the Sun, as shown by in-situ measurements near 1AU. However, for solar…

Solar and Stellar Astrophysics · Physics 2022-09-14 Xiangrong Fu , Hui Li , Zhaoming Gan , Senbei Du , John Steinberg

Observations of radio signals from distant pulsars provide a valuable tool for investigation of interstellar turbulence. The time-shapes of the signals are the result of pulse broadening by the fluctuating electron density in the…

Astrophysics · Physics 2007-05-23 Stanislav Boldyrev , Carl R. Gwinn

The description of the local turbulent energy transfer, and the high-resolution ion distributions measured by the Magnetospheric Multiscale mission, together provide a formidable tool to explore the cross-scale connection between the…

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

A stochastic differential equation for the plasma density dynamics is derived, consistent with the experimentally measured distribution and the theoretical quadratic nonlinearity. The plasma density is driven by a multiplicative Wiener…

Plasma Physics · Physics 2012-10-05 A. Mekkaoui

Interaction of impulsively generated MHD waves with a one-dimensional plasma inhomogeneity, transverse to the magnetic field, is considered in the three-dimensional regime. Because of the transverse inhomogeneity, MHD fluctuations, even if…

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

The density structure of the interstellar medium (ISM) determines where stars form and release energy, momentum, and heavy elements, driving galaxy evolution. Density variations are seeded and amplified by gas motion, but the exact nature…

The interstellar medium (ISM) of our Galaxy is magnetized, compressible and turbulent, influencing many key ISM properties, like star formation, cosmic ray transport, and metal and phase mixing. Yet, basic statistics describing…

Astrophysics of Galaxies · Physics 2025-05-15 James R. Beattie , Christoph Federrath , Ralf S. Klessen , Salvatore Cielo , Amitava Bhattacharjee

The rich structure that we observe in molecular clouds is due to the interplay between strong magnetic fields and supersonic (turbulent) velocity fluctuations. The velocity fluctuations interact with the magnetic field, causing it too to…

Astrophysics of Galaxies · Physics 2020-08-12 James R. Beattie , Christoph Federrath , Amit Seta

The properties of low-frequency convective fluctuations and transport are investigated for the boundary region of magnetized plasmas. We employ a two-dimensional fluid model for the evolution of the global plasma quantities in a geometry…

Plasma Physics · Physics 2007-05-23 Odd Erik Garcia , Volker Naulin , Anders Henry Nielsen , Jens Juul Rasmussen

We have recently proposed a mechanism of photon-axion oscillations as a way of rendering supernovae dimmer without cosmic acceleration. Subsequently, it has been argued that the intergalactic plasma may interfere adversely with this…

High Energy Physics - Phenomenology · Physics 2009-09-17 Csaba Csaki , Nemanja Kaloper , John Terning

This chapter reviews the nature of turbulence in the Galactic interstellar medium (ISM) and its connections to the star formation (SF) process. The ISM is turbulent, magnetized, self-gravitating, and is subject to heating and cooling…

Astrophysics of Galaxies · Physics 2017-03-15 Enrique Vazquez-Semadeni

We study compressible MHD turbulence, which holds key to many astrophysical processes, including star formation and cosmic ray propagation. To account for the variations of the magnetic field in the strongly turbulent fluid we use wavelet…

Astrophysics of Galaxies · Physics 2015-05-18 Grzegorz Kowal , Alex Lazarian

Parker instability arises from the presence of magnetic fields in a plasma in a gravitational field such as the interstellar medium (ISM), wherein the magnetic buoyant pressure expels the gas and causes the gas to move along the field…

High Energy Astrophysical Phenomena · Physics 2011-09-07 Chih-Yueh Wang , Ying-Yi Lo , Chung-Ming Ko

We present results from two-dimensional numerical simulations of a supersonic turbulent flow in the plane of the galactic disk, incorporating shear, thresholded and discrete star formation (SF), self-gravity, rotation and magnetic fields. A…

Astrophysics · Physics 2009-10-28 T. Passot , E. Vazquez-Semadeni , A. Pouquet

In this paper we show results of numerical simulations for the turbulence in the interstellar medium. These results were obtained using a Riemann solver-free numerical scheme for high-Mach number hyperbolic equations. Here we especially…

Astrophysics of Galaxies · Physics 2011-02-11 R. Kissmann , J. Kleimann , H. Fichtner , R. Grauer

The relationship between a decaying plasma turbulence and proton fire hose instabilities in a slowly expanding plasma is investigated using three-dimensional (3-D) hybrid expanding box simulations. We impose an initial ambient magnetic…

Space Physics · Physics 2019-10-10 P. Hellinger , L. Matteini , S. Landi , L. Franci , A. Verdini , E. Papini

In low-density plasma environments, such as the intracluster medium (ICM), the Larmour frequency is much larger than the ion-ion collision frequency. In such a case, the thermal pressure becomes anisotropic with respect to the magnetic…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 M. S. Nakwacki , E. M. de Gouveia Dal Pino , G. Kowal , R. Santos-Lima

In weakly collisional extragalactic plasmas such as the intracluster medium, viscous stress and the rate of change of the magnetic-field strength are proportional to the local pressure anisotropy, so subject to constraints imposed by the…

Cosmology and Nongalactic Astrophysics · Physics 2015-08-26 Federico Mogavero , Alexander A. Schekochihin