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Related papers: KAPPA: A Package for Synthesis of optically thin s…

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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

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…

Solar and Stellar Astrophysics · Physics 2015-09-09 Michael Hahn , Daniel Wolf Savin

New data for calculation of the ionization and recombination rates have have been published in the past few years. Most of these are included in CHIANTI database. We used these data to calculate collisional ionization and recombination…

Solar and Stellar Astrophysics · Physics 2013-05-08 Elena Dzifcakova , Jaroslav Dudik

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

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

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

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…

Solar and Stellar Astrophysics · Physics 2015-06-12 M. Oka , S. Ishikawa , P. Saint-Hilaire , S. Krucker , R. P. Lin

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…

Solar and Stellar Astrophysics · Physics 2019-06-19 Jaroslav Dudik , Elena Dzifcakova , Giulio Del Zanna , Helen E. Mason , Leon L. Golub , Amy R. Winebarger , Sabrina L. Savage

Kappa-distributed velocities in plasmas are common in a wide variety of settings, from low-density to high-density plasmas. To date, they have been found mainly in space plasmas, but are recently being considered also in the modelling of…

Statistical Mechanics · Physics 2025-03-25 Sergio Davis , Gonzalo Avaria , Biswajit Bora , Jalaj Jain , José Moreno , Cristian Pavez , Leopoldo Soto

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…

Solar and Stellar Astrophysics · Physics 2018-02-14 Elena Dzifcakova , Alena Zemanova , Jaroslav Dudik , Simon Mackovjak

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

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…

Plasma Physics · Physics 2021-09-16 Bojan Arbutina , Vladimir Zekovic

We have developed an analytic model to describe coupling of plasma and neutral fluids in the partially ionized heliosphere plasma medium. The sources employed in our analytic model are based on a $\kappa$-distribution as opposed to the…

Space Physics · Physics 2015-05-19 Dastgeer Shaikh , B Dasgupta

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…

Solar and Stellar Astrophysics · Physics 2017-06-21 Jaroslav Dudik , Vanessa Polito , Elena Dzifcakova , Giulio Del Zanna , Paola Testa

The kappa distribution of velocities appears routinely in the study of collisionless plasmas present in Earth's magnetosphere, the solar wind among other contexts where particles are unable to reach thermal equilibrium. Originally justified…

Statistical Mechanics · Physics 2025-10-28 Sergio Davis , Biswajit Bora , Cristian Pavez , Leopoldo Soto

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

From the perspective of non-equilibrium statistical mechanics, modeling the velocity distribution of particles in non-equilibrium, steady-state plasmas presents a significant challenge. Under this context, a family of kappa distributions…

Plasma Physics · Physics 2025-09-10 Abiam Tamburrini , Sergio Davis , Pablo S. Moya

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…

Solar and Stellar Astrophysics · Physics 2015-12-16 Marina Battaglia , Galina Motorina , Eduard P. Kontar

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…

Solar and Stellar Astrophysics · Physics 2009-11-13 J. Kasparova , M. Karlicky

Thermal Doppler broadening of spectral profiles for particle populations in the absence or presence of potential fields are described by kappa distributions. The kappa distribution provides a replacement for the Maxwell-Boltzmann…

Solar and Stellar Astrophysics · Physics 2024-08-01 Arak M. Mathai , Hans J. Haubold
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