相关论文: Non-equilibrium hydrogen ionization in 2D simulati…
The ionization state of the gas in the dynamic solar chromosphere can depart strongly from the instantaneous statistical equilibrium commonly assumed in numerical modeling. We improve on earlier simulations of the solar atmosphere that only…
An approximate method for solving the rate equations for the hydrogen populations was extended and implemented in the three-dimensional radiation (magneto-)hydrodynamics code CO5BOLD. The method is based on a model atom with six energy…
The thermal structure of the chromosphere is regulated through a complex interaction of various heating processes, radiative cooling, and the ionization degree of the plasma. Here we study the impact on the thermal properties of the…
Our aim is to determine the dominant processes and timescales for the ionisation equilibrium of calcium under solar chromospheric conditions. The study is based on numerical simulations with the RADYN code, which includes hydrodynamics,…
We investigate the ionization of hydrogen in a dynamic Solar atmosphere. We show that the time scale for ionization/recombination can be estimated from the eigenvalues of a modified rate matrix where the optically thick Lyman transitions…
Detailed numerical models of chromosphere and corona are required to understand the heating of the solar atmosphere. An accurate treatment of the solar chromosphere is complicated by the effects arising from Non Local Thermodynamic…
Understanding the dynamics of the solar chromosphere is crucial to understanding energy transport across the solar atmosphere. The chromosphere is optically thick at many wavelengths and described by non-local thermodynamic equilibrium…
Helium ionization plays an important role in the energy balance of the upper chromosphere and transition region. Helium spectral lines are also often used as diagnostics of these regions. We carry out 1D radiation-hydrodynamics simulations…
We investigate a non-equilibrium ionization state and an electron-ion two-temperature structure of the intracluster medium (ICM) in merging galaxy clusters using a series of N-body and hydrodynamic simulations. Mergers with various sets of…
We investigate the synthesis of the Balmer and Paschen lines of the quiet Sun, using both classical semi-empirical and theoretical model atmospheres, modern line broadening theory and non-LTE line-formation. The computations alleviate…
Magnetic flux emergence has been shown to be a key mechanism for unleashing a wide variety of solar phenomena. However, there are still open questions concerning the rise of the magnetized plasma through the atmosphere, mainly in the…
The solar chromosphere is weakly ionized and interactions between ionized particles and neutral particles likely have significant consequences for the thermodynamics of the plasma. We investigate the importance of introducing neutral…
An initial theoretical attempt to explain the observed decrease of the polytropic/adiabatic index $\gamma$ in the solar corona has been accomplished. The chemical reactions of the ionization-recombination processes in local thermodynamic…
We performed the non-local thermodynamic equilibrium (non-LTE) calculations for Ti I-II with the updated model atom that includes quantum-mechanical rate coefficients for inelastic collisions with hydrogen atoms. We have calculated for the…
The solar transition region (TR) is a narrow interface between the chromosphere and corona, where emitted radiation contains critical information pertinent to coronal heating processes. We conducted 2-dimensional radiation…
Explosive phenomena are known to trigger a wealth of shocks in warm plasma environments, including the solar chromosphere and molecular clouds where the medium consists of both ionised and neutral species. Partial ionisation is critical in…
During transient events such as major solar eruptions, the plasma can be far from the equilibrium ionization state because of rapid heating or cooling. Non-equilibrium ionization~(NEI) is important in rapidly evolving systems where the…
X-ray imaging observatories have revealed hydrodynamic structures with linear scales ~ 10 kpc in clusters of galaxies, such as shock waves in the 1E0657-56 and A520 galaxy clusters and the hot plasma bubble in the MKW 3s cluster. The future…
Shocks are a universal feature of the lower solar atmosphere which consists of both ionised and neutral species. Including partial ionisation leads to a finite-width existing for shocks, where the ionised and neutral species decouple and…
The negative hydrogen ion H$^-$ is, almost without exception, treated in local thermodynamic equilibrium (LTE) in the modelling of F, G, and K stars, where it is the dominant opacity source in the visual spectral region. This assumption…