Related papers: Expansion of Hot Plasma into Cold Plasma
Observations suggest that in normal period radio pulsars, coherent curvature radiation is excited within 10$\%$ of the light cylinder. The coherence is attributed to Langmuir mode instability in a relativistically streaming one-dimensional…
Aims. Optically thin plasmas may deviate from thermal equilibrium and thus, electrons (and ions) are no longer described by the Maxwellian distribution. Instead they can be described by $\kappa$-distributions. The free-free spectrum and…
Currently there is a concern about ability of the classical thermal (Maxwellian) distribution to describe quasi-steady-state plasma in solar atmosphere including active regions. In particular, other distributions have been proposed to…
We consider electron acceleration by obliquely propagating fast mode waves in magnetically dominated accretion disk coronae. For low coronal plasma densities, acceleration can exceed Coulomb drag at lower energies and energize electrons out…
In a solar flare, a large fraction of the magnetic energy released is converted rapidly to the kinetic energy of non-thermal particles and bulk plasma motion. This will likely result in non-equilibrium particle distributions and turbulent…
A vexing puzzle in the study of planetary nebulae and \ion{H}{2} regions is that the plasma diagnostic results based on collisionally excited lines systematically differ from those based on recombination lines. A fairly speculative…
This paper analyzes a situation which is common for magnetized technical plasmas such as dc magnetron discharges and HiPIMS systems, where secondary electrons enter the plasma after being accelerated in the cathode fall and encounter a…
Non-thermal electron populations are observed throughout the heliosphere. The relaxation of an electron beam is known to produce Langmuir waves which, in turn, may substantially modify the electron distribution function. As the Langmuir…
The nonlinear dynamics of electron-acoustic localized structures in a collisionless and unmagnetized plasma consisting of "cool" inertial electrons, "hot" electrons having a kappa distribution, and stationary ions is studied. The…
Three-wave interactions between Langmuir and electromagnetic waves in plasma with unstable electron flows are believed to be the main cause for type II and III solar radio emissions. The narrow band of type II bursts requires to assume that…
X-ray emission provides the most direct diagnostics of the energy-release process in solar flares. Occasionally, a superhot X-ray source is found to be above hot flare loops of ~10 MK temperature. While the origin of the superhot plasma is…
By using the generalized Boltzmann equation of transport and the first-order approximation of Chapman-Enskog expansion on the kappa-distribution function, we study the thermal conductivity and Dufour effects in the weakly ionized and…
Type III radio bursts are a signature of the flux of near-relativistic electrons ejected during solar flares. These bursts are frequently observed by spacecraft such as the Parker Solar Probe. It is traditionally believed that these…
Very hot plasmas with ion temperature exceeding $10^{10}$ K can be formed in certain astrophysical environments. The distinct radiation signature of such plasmas is the $\gamma$-ray emission dominated by the prompt de-excitation nuclear…
Velocity distribution functions (VDFs) that exhibit a power-law dependence on the high-energy tail have been the subject of intense research by the plasma physics community. Such functions, known as kappa or superthermal distributions, have…
The thermal collapse of a nearly collisionless plasma interacting with a cooling spot, in which the electron parallel heat flux plays an essential role, is investigated both theoretically and numerically. We show that such thermal collapse,…
Recently, a number of peculiar flares have been reported, which demonstrate significant non-thermal particle signatures with a low, if any, thermal emission, that implies close association of the observed emission with the primary energy…
The high energy continuum in Seyfert galaxies and galactic black hole candidates is likely to be produced by a thermal plasma. There are difficulties in understanding what can keep the plasma thermal, especially during fast variations of…
Optical/UV radiation from accretion disks in quasars is likely to be partly scattered by a hot plasma enveloping the disk. We investigate whether the scattering may produce the steep rises in polarization observed blueward of the Lyman…
The waves generated by high-energy proton and alpha particles streaming from solar flares into regions of colder plasma are explored using particle-in-cell simulations. Initial distribution functions for the protons and alphas consist of…