相关论文: Ionization in Atmospheres of Brown Dwarfs and Extr…

Radio and X-ray emission from brown dwarfs suggest that an ionised gas and a magnetic field with a sufficient flux density must be present. We perform a reference study for late M-dwarfs, brown dwarfs and giant gas planet to identify which…

Observations have shown that continuous radio emission and also sporadic H-alpha and X-ray emission are prominent in singular, low-mass objects later than spectral class M. These activity signatures are interpreted as being caused by…

Brown dwarfs emit bursts of Halpha, white light flares, and show radio flares and quiescent radio emission. They are suggested to form Aurorae, similar to planets in the solar system but much more energetic. All these processes require a…

Cosmic rays provide an important source for free electrons in the Earth's atmosphere and also in dense interstellar regions where they produce a prevailing background ionization. We utilize a Monte Carlo cosmic ray transport model for…

In the solar atmosphere, the chromospheric and coronal plasmas are much hotter than the visible photosphere. The heating of the solar atmosphere, including the partially ionized chromosphere and corona, remains largely unknown. In this…

Brown dwarfs and giant gas extrasolar planets have cold atmospheres with a rich chemical compositions from which mineral cloud particles form. Their properties, like particle sizes and material composition, vary with height, and the mineral…

Two scenarios of possible ion heating due to finite amplitude parallel propagating Alfv\'en waves in the solar atmosphere are investigated using a 1D test particle approach. 1. An finite amplitude Alfv\'en wave is instantly introduced into…

Alfv\'en waves are a particular class of magnetohydrodynamic waves relevant in many astrophysical and laboratory plasmas. In partially ionized plasmas the dynamics of Alfv\'en waves is affected by the interaction between ionized and neutral…

Finite-amplitude low-frequency Alfv\'en waves are commonly found in plasma environments, such as space plasmas, and play a crucial role in ion heating. The nonlinear interaction between oblique Alfv\'en wave spectra and ions has been…

The overshooting convective motions in the solar photosphere are frequently proposed as the source for the excitation of Alfv\'en waves. However, the photosphere is a) very weakly ionized, and, b) the dynamics of the plasma particles in…

Pseudoheating of ions in the presence of Alfv\'en waves is studied. We show that this process can be explained by $E\times B$ drift. The analytic solution obtained in this paper are quantitatively in accordance with previous results. Our…

Phase mixing of Alfven waves is one of the most promising mechanisms for heating of the solar atmosphere. The damping of waves in this case requires small transversal scales, relative to the magnetic field direction. Here this requirement…

This work is an extension of Kaghashvili [1999] where ion-cyclotron wave dissipation channel for Alfv\'en waves was discussed. While our earlier study dealt with the mode coupling in the commonly discussed sense, here we study changes in…

Using the recently observed torsional Alfv\'en waves in solar prominences, we determine the ionisation state of the plasma by taking into account that Alfv\'en waves propagate in a partially ionised prominence plasma. We derive the…

Rockets and satellites have previously observed small-scale Alfv\'en waves inside large-scale downward field-aligned currents and numerical simulations have associated their formation with self-consistent magnetosphere-ionosphere coupling.…

Mineral clouds in substellar atmospheres play a special role as a catalyst for a variety of charge processes. If clouds are charged, the surrounding environment becomes electrically activated, and ensembles of charged grains are…

Cold (eV) ions of ionospheric origin are a major source of magnetospheric plasma. These ions dominate the number density for most of the volume of the magnetosphere, most of the time. This affects large-scale physics, including plasma…

The photospheric temperature minimum in the Sun and solar-like stars is very weakly ionized, with ionization fraction $f$ as low as $10^{-4}$. In galactic star forming regions, $f$ can be $10^{-10}$ or lower. Under these circumstances, the…

The characteristics of Alfv\'en waves propagating in a direction oblique to the ambient magnetic field in a stellar wind environment are discussed. A kinetic formulation for a magnetized dusty plasma is adopted considering Maxwellian…

Phase mixing has long been understood to be a viable mechanism for expediting the dissipation of Alfv\'en wave energy resulting in the subsequent heating of the solar atmosphere. To fulfil the conditions necessary for phase mixing to occur,…