English
Related papers

Related papers: Parametric instability in dark molecular clouds

200 papers

This letter discusses rotating magnetohydrodynamics (MHD) of a thin layer of astrophysical plasma. To describe a thin plasma layer with a free surface in a vertical external magnetic field we use the shallow water ap- proximation. The…

Solar and Stellar Astrophysics · Physics 2015-12-08 Dmitry Klimachkov , Arakel Petrosyan

Thermal electrons cannot directly participate in the process of diffusive acceleration at electron-ion shocks because their Larmor radii are smaller than the shock transition width: this is the well-known electron injection problem of…

High Energy Astrophysical Phenomena · Physics 2022-06-29 Mohamad Shalaby , Rouven Lemmerz , Timon Thomas , Christoph Pfrommer

We study magnetothermal instability in the ionized plasmas including the effects of Ohmic, ambipolar and Hall diffusion. Magnetic field in the single fluid approximation does not allow transverse thermal condensations, however, non-ideal…

Solar and Stellar Astrophysics · Physics 2014-11-20 Mohsen Shadmehri , Mohsen Nejad-Asghar , Alireza Khesali

The possibility of slow diffusion regions as the origin for extended TeV emission halos around some pulsars (such as PSR J0633+1746 and PSR B0656+14) challenges the standard scaling of the electron diffusion coefficient in the interstellar…

High Energy Astrophysical Phenomena · Physics 2024-08-14 Illya Plotnikov , Allard Jan van Marle , Claire Guépin , Alexandre Marcowith , Pierrick Martin

It has been shown that magnetic fields play an important role in the stability of molecular clouds, mainly perpendicularly to the field direction. However, in the parallel direction the stability is a serious problem still to be explained.…

Astrophysics · Physics 2009-11-10 D. Falceta-Goncalves , V. Jatenco-Pereira , M. de Juli

This study investigates Parker instability in an interstellar medium (ISM) near the Galactic plane using three-dimensional magneto-hydrodynamic simulations. Parker instability arises from the presence of a magnetic field in a plasma,…

High Energy Astrophysical Phenomena · Physics 2011-01-06 Ying-Yi Lo , Chung-Ming Ko , Chih-Yueh Wang

We study the stability of shear flows in a fully ionized plasma. Kelvin-Helmholtz is a well known, macroscopic and ideal shear-driven instability. In sufficiently low density plasmas, also the microscopic Hall magneto-shear instability can…

High Energy Astrophysical Phenomena · Physics 2014-05-27 Daniel O. Gomez , Cecilia Bejarano , Pablo D. Mininni

The thin-shell instability has been named as one process, which can generate entangled structures in astrophysical plasma on collisional (fluid) scales. It is driven by a spatially varying imbalance between the ram pressure of the inflowing…

High Energy Astrophysical Phenomena · Physics 2015-09-30 M. E. Dieckmann , H. Ahmed , D. Doria , G. Sarri , R. Walder , D. Folini , A. Bret , A. Ynnerman , M. Borghesi

An object's wake in a plasma with small Debye length that drifts \emph{across} the magnetic field is subject to electrostatic electron instabilities. Such situations include, for example, the moon in the solar wind wake and probes in…

Plasma Physics · Physics 2015-03-27 I. H. Hutchinson , C. B. Haakonsen , C. Zhou

Plasma processes close to SNR shocks result in the amplification of magnetic fields and in the acceleration of electrons, injecting them into the diffusive acceleration mechanism. The acceleration of electrons and the B field amplification…

High Energy Astrophysical Phenomena · Physics 2015-06-09 M E Dieckmann , G Murphy , A Meli , L O C Drury

We study collective processes for an electron beam propagating through a background plasma using simulations and analytical theory. A new regime where the instability of a Langmuir wave packet can grow locally much faster than ion frequency…

Plasma Physics · Physics 2022-10-05 Haomin Sun , Jian Chen , Igor D. Kaganovich , Alexander Khrabrov , Dmytro Sydorenko

Analytic treatment is presented of the electrostatic instability of an initially planar electron hole in a plasma of effectively infinite particle magnetization. It is shown that there is an unstable mode consisting of a rigid shift of the…

Plasma Physics · Physics 2019-09-25 I H Hutchinson

Observations of molecular clouds show the existence of starless, dense cores, threaded by magnetic fields. Observed line widths indicate these dense condensates to be embedded in a supersonically turbulent environment. Under these…

Astrophysics · Physics 2009-11-10 Doris Folini , Jean Heyvaerts , Rolf Walder

Ion-neutral collisions may lead to the damping of Alfven waves in chromospheric and prominence plasmas. Neutral helium atoms enhance the damping in certain temperature interval, where the ratio of neutral helium and neutral hydrogen atoms…

Solar and Stellar Astrophysics · Physics 2015-06-12 T. V. Zaqarashvili , M. L. Khodachenko , R. Soler

The Probability Distribution Function of plasma density fluctuations at the edge of fusion devices is known to be skewed and strongly non-Gaussian. The causes of this peculiar behaviour are, up to now, largely unexplored. On the other hand,…

Plasma Physics · Physics 2007-05-23 F. Sattin , N. Vianello

The growth rate of the filamentation instability triggered when a diluted cold electron beam passes through a cold plasma is evaluated using the quantum hydrodynamic equations. Compared with a cold fluid model, quantum effects reduce both…

Plasma Physics · Physics 2009-11-13 A. Bret

Theoretical approaches to low-frequency magnetized turbulence in collisionless and weakly collisional astrophysical plasmas are reviewed. The proper starting point for an analytical description of these plasmas is kinetic theory, not fluid…

Astrophysics · Physics 2009-11-11 A. A. Schekochihin , S. C. Cowley , W. Dorland

This paper is devoted to the study of the gravitational instability of a medium permeated by a uniform magnetic field along which a circularly polarized Alfven wave propagates. We concentrate on the case of perturbations purely transverse…

Astrophysics · Physics 2009-11-07 Adriana Gazol , Thierry Passot

Particle acceleration at astrophysical shocks may be very efficient if magnetic scattering is self-generated by the same particles. This nonlinear process adds to the nonlinear modification of the shock due to the dynamical reaction of the…

Astrophysics · Physics 2009-11-11 Elena Amato , Pasquale Blasi

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
‹ Prev 1 3 4 5 6 7 10 Next ›