Related papers: Deriving the Coronal Hole Electron Temperature: El…
The brightness of the emission from coronal loops in the solar atmosphere is strongly dependent on the temperature and density of the confined plasma. After a release of energy, these loops undergo a heating and upflow phase, followed by a…
The EUI instrument on the Solar Orbiter spacecraft has obtained the most stable, high-resolution images of the solar corona from its orbit with a perihelion near 0.4 AU. A sequence of 360 images obtained at 17.1 nm, between 25-Oct-2022…
A technique is described for measuring electrical currents in the solar corona. It uses radioastronomical polarization measurements of a spatially-extended radio source viewed through the corona. The observations yield the difference in the…
We present the results of two-temperature magnetohydrodynamic simulations of the propagation of sub-relativistic jets of active galactic nuclei. The dependence of the electron and ion temperature distributions on the fraction of electron…
I explore the thermal evolution and ionization states in gas cooling from an initially hot state in the presence of external photoionizing radiation. I compute the equilibrium and nonequilibrium cooling efficiencies, heating rates, and ion…
We review X-ray plasma diagnostics based on the line ratios of He-like ions. Triplet/singlet line intensities can be used to determine electronic temperature and density, and were first developed for the study of the solar corona. Since the…
The aim of this work is to improve the modelling of ion populations in higher density, lower temperature astrophysical plasmas, of the type commonly found in lower solar and stellar atmospheres. Ion population models for these regions…
The Event Horizon Telescope (EHT) collaboration, an Earth-size sub-millimetre radio interferometer, recently captured the first images of the central supermassive black hole in M87. These images were interpreted as gravitationally-lensed…
In the article an ultracold electron-ion plasma created by photoionization of cooled atoms is investigated. We obtained analitical expressions for non-ideality parameters which establish due to correlation heating. In the work the nearest…
Context. The radiative energy balance in the solar chromosphere is dominated by strong spectral lines that are formed out of LTE. It is computationally prohibitive to solve the full equations of radiative transfer and statistical…
We calculate the electron recombination rates with target ions W$^{q+}$, $q = 18$ -- $25$, as functions of electron energy and electron temperature (i.e. the rates integrated over the Maxwellian velocity distribution). Comparison with…
We use full-disk, SOHO/EIT 195 $\AA$ calibrated images to measure latitudinal and day to day variations of area and average photon fluxes of the near equatorial coronal holes. In addition, energy emitted by the coronal holes with their…
The detailed knowledge of plasma heating and acceleration region properties presents a major observational challenge in solar flare physics. Using the Ramaty High Energy Solar Spectroscopic Imager (RHESSI), the high temperature differential…
Ion resonance instability of toroidal electron plasmas in a tight aspect ratio axisymmetric toroidal device is reported for ${Ar}^+$ ions of different initial density values using a high fidelity 3D3V PIC solver. Stability of a recently…
(Abridged) We use high S/N spectra of 20 HII regions in the giant spiral galaxy M101 to derive electron temperatures for the HII regions and robust metal abundances over radii R = 0.19-1.25 Ro (6-41 kpc). We compare the consistency of…
Coronal heating through the explosive release of magnetic energy remains an open problem in solar physics. Recent hydrodynamical models attempt an investigation by placing swarms of 'nanoflares' at random sites and times in modeled…
We develop a self-consistent model for the equilibrium gas temperature and size-dependent dust temperature in cold, dense pre-stellar cores, assuming an arbitrary power-law size distribution of dust grains. Compact analytical expressions…
Coronal mass ejections (CMEs) are often associated with coronal dimmings, i.e. transient dark regions that are most distinctly observed in Extreme Ultra-violet (EUV) wavelengths. Using Atmospheric Imaging Assembly (AIA) data, we apply…
We study temperature and density sensitivities of ratios of Si XI soft X-ray emission lines, in the wavelength range of 43--54\AA . The typical temperature of the formation of the analyzed lines is around 1.6~MK, which makes this analysis…
We perform a time-dependent ionization analysis to constrain plasma heating requirements during a fast partial halo coronal mass ejection (CME) observed on 2000 June 28 by the Ultraviolet Coronagraph Spectrometer (UVCS) aboard the Solar and…