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Related papers: H to Zn Ionization Equilibrium for the Non-Maxwell…

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In astronomical environments, the high-temperature emission of plasma mainly depends on ion charge states, which requires accurate analysis of the ionization and recombination processes. For various phenomena involving energetic particles,…

Solar and Stellar Astrophysics · Physics 2025-06-18 Chengcai Shen , Xiaocan Li , Yuan-Kuen Ko , John C. Raymond , Fan Guo , Vanessa Polito , Viviane Pierrard

The KAPPA package is designed for calculations of optically thin spectra for the non-Maxwellian \k{appa}-distributions. This paper presents extension of the database to allow calculations of the spectra for extreme values of \k{appa} < 2,…

Solar and Stellar Astrophysics · Physics 2023-10-10 Elena Dzifcakova , Jaroslav Dudik , Martina Pavelkova , Bozena Solarova , Alena Zemanova

The non-Maxwellian $\kappa$-distributions have been detected in the solar transition region and flares. These distributions are characterized by a high-energy tail and a near-Maxwellian core and are known to have significant impact on the…

Solar and Stellar Astrophysics · Physics 2015-06-23 Elena Dzifčáková , Jaroslav Dudík , Pavel Kotrč , František Fárník , Alena Zemanová

Reliably interpreting spectra from electron-ionized cosmic plasmas requires accurate ionization balance calculations for the plasma in question. However, much of the atomic data needed for these calculations have not been generated using…

Astrophysics · Physics 2009-11-11 P. Bryans , N. R. Badnell , T. W. Gorczyca , J. M. Laming , W. Mitthumsiri , D. W. Savin

We provide a data set of emission and recombination coefficients of hydrogen using a kappa-distribution of electron energies rather than the more traditional Maxwell-Boltzmann (MB) distribution. The data are mainly relevant to thin and…

Atomic Physics · Physics 2014-11-25 P. J. Storey , Taha Sochi

We have investigated the effects of a non-thermal electron population on the ionization and recombination rates. The considered electron distribution is defined as a Maxwellian function below a break energy E_b and as a power-law function…

Astrophysics · Physics 2009-11-06 D. Porquet , M. Arnaud , A. Decourchelle

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…

Solar and Stellar Astrophysics · Physics 2020-08-19 Bao-Zhi Lin , Yong Zhang

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…

Astrophysics of Galaxies · Physics 2021-06-29 S. G. Morais , A. Humphrey , M. Villar Martín , L. Binette , M. Silva

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…

Solar and Stellar Astrophysics · Physics 2014-11-05 J. Dudík , G. Del Zanna , H. E. Mason , E. Dzifčáková

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…

Solar and Stellar Astrophysics · Physics 2024-03-26 R. P. Dufresne , G. Del Zanna , P. R. Young , K. P. Dere , E. Deliporanidou , W. T. Barnes , E. Landi

Some authors have proposed that electron energy distributions in H II regions and planetary nebulae may be significantly nonthermal, and kappa-distributions have been suggested as being appropriate. Here it is demonstrated that the electron…

Astrophysics of Galaxies · Physics 2018-07-23 B. T. Draine , C. D. Kreisch

The CHIANTI atomic database provides sets of assessed data used for simulating spectral observations of astrophysical plasmas. This article describes updates that will be released as version~10.1 of the database. A key component of CHIANTI…

Atomic Physics · Physics 2023-08-23 Kenneth Dere , Giulio Del Zanna , Peter Young , Enrico Landi

The measurement of electron temperatures and metallicities in H ii regions and Planetary Nebulae (PNe) has-for several decades-presented a problem: results obtained using different techniques disagree. What it worse, they disagree…

Astrophysics of Galaxies · Physics 2012-06-20 David C. Nicholls , Michael A. Dopita , Ralph S. Sutherland

The classic optical nebular diagnostics [N II], [O II], [O III], [S II], [S III], and [Ar III] are employed to search for evidence of non-Maxwellian electron distributions, namely $\kappa$ distributions, in a sample of well-observed…

Instrumentation and Methods for Astrophysics · Physics 2015-06-18 C. Mendoza , M. A. Bautista

Shocks, turbulence and winds all influence the electron velocity distribution in hot plasmas, exciting lower-energy electrons and generating a high-energy (typically power-law) tail. This effect, typically described as a kappa distribution…

Solar and Stellar Astrophysics · Physics 2020-01-08 Xiaohong Cui , Adam R. Foster , Takayuki Yuasa , Randall K. Smith

Recently, a suspicion arose that the free electrons in planetary nebulae (PNe) and HII regions might have non-thermal energy distributions. In this scenario, a kappa index is introduced to characterize the electron energy distributions,…

Solar and Stellar Astrophysics · Physics 2016-02-10 Yong Zhang , Bing Zhang , Xiao-Wei Liu

We present in this paper new and updated calculations of the ionization equilibrium for all the elements from H to Ni. We collected for these elements all the data available in the literature for the ionization and radiative plus…

Astrophysics · Physics 2009-10-30 P. Mazzotta , G. Mazzitelli , S. Colafrancesco , N. Vittorio

Photoionization produces supra-thermal electrons, electrons with much more energy than is found in a thermalized gas at electron temperatures characteristic of nebulae. The presence of these high energy electrons may solve the long-standing…

Solar and Stellar Astrophysics · Physics 2016-05-13 G. J. Ferland , W. J. Henney , C. R. ODell , M. Peimbert

Recently, \citet{Nicholls12}, inspired by \emph{in situ} observations of solar system astrophysical plasmas, suggested that the electrons in \HII regions are characterised by a $\kappa$-distribution of electron energies rather than by a…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 Michael A. Dopita , Ralph S. Sutherland , David C. Nicholls , Lisa J. Kewley , Frédéric P. A. Vogt

An important aspect of solar energetic particle (SEP) events is their source populations. Elemental abundance enhancements of impulsive SEP events, originating in presumed coronal reconnection episodes, can be fitted to steep power laws of…

Solar and Stellar Astrophysics · Physics 2024-03-12 Jin-Yi Lee , Stephen Kahler , John C. Raymond , Yuan-Kuen Ko
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