相关论文: Nonlinear Alfv\'en Wave Model of Stellar Coronae a…
We study the propagation and transmission of Alfven waves in the context of cylindrical geometry. This approximates the polar cap region of aligned pulsar with strong magnetic fields. Non-propagating region appears in the presence of…
The subject of this study is oscillations in the lower atmosphere in coronal-hole regions, where the conditions are favorable for propagation between the atmospheric layers. Based on spectroscopic observations in photospheric and…
Stars interact with their planets through gravitation, radiation, and magnetic fields. Although magnetic activity decreases with time, reducing associated high-energy (e.g., coronal XUV emission, flares), stellar winds persist throughout…
The measured spectrum of kinetic Alfven wave fluctuations in the turbulent solar wind plasma is used to calculate the electron and ion distribution functions resulting from quasi-linear diffusion. The modified ion distribution function is…
We investigate mass losses via stellar winds from sun-like main sequence stars with a wide range of activity levels. We perform forward-type magnetohydrodynamical numerical experiments for Alfven wave-driven stellar winds with a wide range…
By performing MHD simulations, we investigate the mass loss of intermediate- and low-mass stars from main sequence (MS) to red giant branch (RGB) phases. Alfven waves, which are excited by the surface convections travel outwardly and…
Large-amplitude Alfv\'en waves are ubiquitous in space plasmas and a main component of magnetohydrodynamic (MHD) turbulence in the heliosphere. As pump waves they are prone to parametric instability by which they can generate cyclotron and…
Alfv\'enic fluctuations of various scales are ubiquitous in the corona; their non-linear interactions and eventual turbulent cascade result in an important heating mechanism that accelerates the solar wind. These fluctuations may be…
Phase-mixing of Alfv\'en waves in the solar corona has been identified as one possible candidate to explain coronal heating. While this scenario is supported by observations of ubiquitous oscillations in the corona carrying sufficient wave…
Flare frequency distributions represent a key approach to addressing one of the largest problems in solar and stellar physics: determining the mechanism that counter-intuitively heats coronae to temperatures that are orders of magnitude…
Recent observations have demonstrated that waves which are capable of carrying large amounts of energy are ubiquitous throughout the solar corona. However, the question of how this wave energy is dissipated (on which time and length scales)…
The weakly non-linear interaction of slow magnetoacoustic and torsional Alfven waves propagating along an unperturbed poloidal magnetic field in a stellar interior is studied in the high plasma beta limit. It is shown that slow…
We study the role the the p-mode-like vertical oscillation on the photosphere in driving solar winds in the framework of Alfven-wave-driven winds. By performing one-dimensional magnetohydrodynamical numerical simulations from the…
Complete asymptotic expansions are developed for slow, Alfv\'en and fast magnetohydrodynamic waves at the base of an isothermal three-dimensional (3D) plane stratified atmosphere. Together with existing convergent Frobenius series solutions…
The elemental composition of the Sun's hot atmosphere, the corona, shows a distinctive pattern that is different than the underlying surface, or photosphere (Pottasch 1963). Elements that are easy to ionize in the chromosphere are enhanced…
Compression of the stellar winds from rapidly rotating hot stars is described by the wind compression model. However, it was also shown that rapid rotation leads to rotational distortion of the stellar surface, resulting in the appearance…
We present a novel method to evaluate the Alfven speed and the magnetic field strength along the streamer plasma sheet in the outer corona. The method is based on recent observations of streamer waves, which are regarded as the fast kink…
Magnetic fields are key ingredients for heating the solar corona to temperatures of several million Kelvin. A particularly important region with respect to this is the so-called magnetic canopy below the corona, where sound and Alfv\'en…
We present results from a kinetic model of collisionless gyrotropic coronal hole protons heated by cyclotron and Landau resonant dissipation of critically balanced kinetic Alfv\'en waves. The model incorporates the kinetic effects of…
We study the magnetospheric structure and the ionospheric Joule Heating of planets orbiting M-dwarf stars in the habitable zone using a set of magnetohydrodynamic (MHD) models. The stellar wind solution is used to drive a model for the…