相关论文: Non-equilibrium Ionization and FIP Effect Diagnost…

We investigate the time evolution of relative elemental abundances in the context of the first ionization potential effect focusing on an active region. Our aim is to characterize this evolution in different types of solar active region…

We describe the effect that new atomic calculations, including fully-relativistic R-matrix calculations of collisional excitation rates and level-specific dielectronic and radiative recombination rates, have on line ratios from the…

It is demonstrated that the ionization events in the vicinity of a small floating grain can increase the ion flux to its surface. In this respect the effect of electron impact ionization is fully analogous to that of the ion-neutral…

The use of the coronal approximation to model line emission from the solar transition region has led to discrepancies with observations over many years, particularly for Li- and Na-like ions. Studies have shown that a number of atomic…

Recent X-ray observations of star-forming galaxies such as M82 have shown the Ly beta/Ly alpha line ratio of Ne X to be in excess of predictions for thermal electron impact excitation. Here we demonstrate that the observed line ratio may be…

Metal-semiconductor contacts are a pillar of modern semiconductor technology. Historically, their microscopic understanding has been hampered by the inability of traditional analytical and numerical methods to fully capture the complex…

We perform a homogeneous analysis of the Fe/Ni abundance ratio in eight Galactic planetary nebulae (PNe) and three Galactic H II regions that include the Orion nebula, where we study four nebular zones and one shocked region. We use [Fe…

Aims: Temperature uncertainties plague our understanding of abundance variations within the ISM. Using the PHANGS-MUSE large program, we develop and apply a new technique to model the strong emission lines arising from HII regions in 19…

Aims: We generate theoretical ultraviolet and extreme-ultraviolet emission line ratios for O IV and show their strong versatility as electron temperature and density diagnostics for astrophysical plasmas. Methods: Recent fully relativistic…

This study on plasma heating considers the time-dependent ionization process during a large solar flare on September 10, 2017, observed by Hinode/EIS. The observed FeXXIV / FeXXIII ratios increase downstream of the reconnection outflow, and…

It is well established that elemental abundances vary in the solar atmosphere and that this variation is organized by first ionization potential (FIP). Previous studies have shown that in the solar corona low-FIP elements, such as Fe, Si,…

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…

Version 11 of the CHIANTI database and software package is presented. Advanced ionization equilibrium models have been added for low charge states of seven elements (C, N, O, Ne, Mg, Si and S), and represent a significant improvement…

The FAC, GRASP2K, and MCDFGME codes are compared in three case study of radiative transitions occurring in tungsten ions: (i) Ni1 and Ni2 lines in Ni-like tungsten, (ii) $3p_{3/2}{-}3p_{1/2}$ fine splitting in Cl-like tungsten, and (iii)…

Studies measuring the chemical abundances of the neutral gas in star-forming galaxies (SFGs) require ionization correction factors (ICFs) to accurately measure their metal contents. In the work presented here we calculate newly improved…

One puzzling question in solar physics is the difference between elemental abundances in the photosphere and the corona. Elements with low first ionization potential (FIP) can be overabundant in the corona compared to the photosphere under…

The analysis of X-ray and Sunyaev-Zel\'dovich measurements of the intracluster medium (ICM) assumes that electrons are in thermal equilibrium with ions in the plasma. However, electron-ion equilibration timescales can be comparable to the…

Line ratio of $3d-2p$ transition lines in boron-like spectra of Si X, S XII, Ar XIV and Fe XXII has been investigated. Collisional-radiative model calculations reveal that the line ratio is sensitive to the electron density in ranges of…

While photoionization rates of Ganymede's O$_2$ dominated atmosphere are well constrained, the contribution of electron-impact ionization is rather uncertain. Previous quantitative estimates have relied on assumptions about densities and…

We present the non-local thermodynamic equilibrium (non-LTE) calculations for O I with the updated model atom that includes quantum-mechanical rate coefficients for O I + H I inelastic collisions from the recent study of Barklem (2018). The…