Related papers: Spectroscopic indication of suprathermal ions in t…
Solar flares produce hard X-ray emission of which the photon spectrum is often represented by a combination of thermal and power-law distributions. However, the estimates of the number and total energy of non-thermal electrons are sensitive…
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…
We investigate the nature of the spectral line profiles for transition region ions observed with the Interface Region Imaging Spectrograph (IRIS). In this context, we have analyzed an active-region observation performed by IRIS in its 1400…
Context. Recent studies on Kappa distribution functions invoked in space plasma applications have emphasized two alternative approaches which may assume the temperature parameter either dependent or independent of the power-index $\kappa$.…
We investigate the possibility of diagnosing the degree of departure from the Maxwellian distribution using single-ion spectra originating in astrophysical plasmas in collisional ionization equilibrium. New atomic data for excitation of Fe…
In situ measurements of the fast solar wind reveal non-thermal distributions of electrons, protons and, minor ions extending from $0.3$ AU to the heliopause. The physical mechanisms responsible for these non-thermal properties and the…
The properties of solar flare plasma can be determined from the observation of optically thin lines. The emitting ion distribution determines the shape of the line, with an isothermal Maxwellian ion distribution producing a Gaussian…
We investigated the possibility of diagnosing the degree of departure from the Maxwellian distribution using the Fe XVII - Fe XVIII spectra originating in plasmas in collisional ionization equilibrium, such as in the cores of solar active…
The profiles of emission lines formed in the corona contain information on the dynamics and the heating of the hot plasma. Only recently has data with sufficiently high spectral resolution become available for investigating the details of…
Acceleration of particles and plasma heating is one of the fundamental problems in solar flare physics. An accurate determination of the spectrum of flare energized electrons over a broad energy range is crucial for our understanding of…
We investigate whether the so-called kappa distribution, often used to fit electron distributions detected in-situ in the solar wind, can describe electrons producing the hard X-ray emission in solar flares. Using Ramaty High Energy Solar…
In this paper we model the high-energy tail of observed solar energetic proton energy distributions with a kappa distribution function. We employ a technique for deriving the thermodynamic parameters of solar energetic proton populations…
Suprathermal tails are a common feature of solar wind electron velocity distributions, and are expected in the solar corona. From the corona, suprathermal electrons can propagate through the steep temperature gradient of the transition…
The departure of particle distributions from the Maxwellian is commonly observed in space plasmas. These non-Maxwellian distributions which are typical for plasmas that are not in thermal equilibrium, can be modeled with…
The X-ray emission of coronal flare sources can be explained considering the kappa electron distribution. Motivated by this fact, we study the problem of how hot plasma with the kappa distribution of electrons is confined in these sources.…
Two independent electron temperature diagnostics applied to the quiet solar corona yield systematically different results. Radio brightness temperatures from the Nancay Radioheliograph indicate T_e ~ 0.6 MK, while hydrostatic scale-height…
There have been several ideas proposed to explain how the Sun's corona is heated and how the solar wind is accelerated. Some models assume that open magnetic field lines are heated by Alfven waves driven by photospheric motions and…
Emission line observations together with photoionization models provide important information about the ionization mechanisms, densities, temperatures, and metallicities in AGN-ionized gas. Photoionization models usually assume…
We demonstrate that a nonthermal distribution of particles described by a kappa distribution can be accurately approximated by a weighted sum of Maxwell-Boltzmann distributions. We apply this method to modeling collision processes in…
Spectroscopic observations made by the Extreme Ultraviolet Variability Experiment (EVE) on board the Solar Dynamics Observatory (SDO) during the 2012 March 7 X5.4-class flare (SOL2012-03-07T00:07) are analyzed for signatures of the…