Boltzmann–Poisson Theory of Nonthermal Self-gravitating Gases, Cold Dark Matter, and Solar Atmosphere

Space and astrophysical plasmas or gases can reach various states of thermal or nonthermal quasi-equilibrium, depending on the collisional age of the observed system. Widely observed in space plasmas, the Kappa (or $\kappa $ —power-law) velocity distribution (KVD) is eloquent evidence of nonthermal...

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Main Authors: L.-N. Hau, C.-K. Chang, M. Lazar, S. Poedts
Format: Article
Language:English
Published: IOP Publishing 2025-01-01
Series:The Astrophysical Journal
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Online Access:https://doi.org/10.3847/1538-4357/ada76f
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author L.-N. Hau
C.-K. Chang
M. Lazar
S. Poedts
author_facet L.-N. Hau
C.-K. Chang
M. Lazar
S. Poedts
author_sort L.-N. Hau
collection DOAJ
description Space and astrophysical plasmas or gases can reach various states of thermal or nonthermal quasi-equilibrium, depending on the collisional age of the observed system. Widely observed in space plasmas, the Kappa (or $\kappa $ —power-law) velocity distribution (KVD) is eloquent evidence of nonthermal states. M. P. Leubner has developed KVD models for luminous gases and cold dark matter (DM) with empirical density profiles described by $\kappa $ > 0 and $\kappa $ < 0, respectively. The predicted temperature profiles, however, are not in qualitative agreement with the nonmonotonic features expected in some gas and DM models. This study adopts the more consistent regularized Kappa distribution (RKD) to derive the equilibrium profiles of self-gravitating gas and DM halos within a Boltzmann–Poisson theoretical approach. The new RKD models can replicate better than the KVD models the Navarro–Frenk–White density profile of the DM near the basic halos and can also produce nonmonotonic temperature profiles. The same RKD formalism is also applied to non-self-gravitating astrophysical systems, which shows that for highly nonthermal cases ( $\kappa \unicode{x0007E}1$ < 3/2), the temperature of the surrounding gases decreases initially in a narrow region. The temperature then increases sharply and reaches a high saturated value, resembling the overheated solar atmosphere, while the density profile near the surface may depart from the observations. Compared to the KVD models, the new RKD models can provide improved descriptions of gravitational equilibrium systems, especially for highly nonthermal cases and temperature profiles.
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spelling doaj-art-7e60d59bc3d7459bb6c9234c82c68a342025-08-20T03:01:32ZengIOP PublishingThe Astrophysical Journal1538-43572025-01-0198111810.3847/1538-4357/ada76fBoltzmann–Poisson Theory of Nonthermal Self-gravitating Gases, Cold Dark Matter, and Solar AtmosphereL.-N. Hau0https://orcid.org/0000-0003-0002-3037C.-K. Chang1https://orcid.org/0000-0001-9051-6307M. Lazar2https://orcid.org/0000-0002-8508-5466S. Poedts3https://orcid.org/0000-0002-1743-0651Department of Space Science and Engineering, National Central University , Taoyuan City, 320317, Taiwan ROC; Department of Physics, National Central University , Taoyuan City, 320317​, Taiwan ROCDepartment of Space Science and Engineering, National Central University , Taoyuan City, 320317, Taiwan ROCCentre for Mathematical Plasma Astrophysics/Department of Mathematics , Celestijnenlaan 200B, B-3001 Leuven, Belgium; Institute for Theoretical Physics IV, Faculty for Physics and Astronomy, Ruhr University Bochum , D-44780 Bochum, GermanyCentre for Mathematical Plasma Astrophysics/Department of Mathematics , Celestijnenlaan 200B, B-3001 Leuven, Belgium; Institute of Physics, University of Maria Curie-Skłodowska , ul. Radziszewskiego 10, 20-031 Lublin, PolandSpace and astrophysical plasmas or gases can reach various states of thermal or nonthermal quasi-equilibrium, depending on the collisional age of the observed system. Widely observed in space plasmas, the Kappa (or $\kappa $ —power-law) velocity distribution (KVD) is eloquent evidence of nonthermal states. M. P. Leubner has developed KVD models for luminous gases and cold dark matter (DM) with empirical density profiles described by $\kappa $ > 0 and $\kappa $ < 0, respectively. The predicted temperature profiles, however, are not in qualitative agreement with the nonmonotonic features expected in some gas and DM models. This study adopts the more consistent regularized Kappa distribution (RKD) to derive the equilibrium profiles of self-gravitating gas and DM halos within a Boltzmann–Poisson theoretical approach. The new RKD models can replicate better than the KVD models the Navarro–Frenk–White density profile of the DM near the basic halos and can also produce nonmonotonic temperature profiles. The same RKD formalism is also applied to non-self-gravitating astrophysical systems, which shows that for highly nonthermal cases ( $\kappa \unicode{x0007E}1$ < 3/2), the temperature of the surrounding gases decreases initially in a narrow region. The temperature then increases sharply and reaches a high saturated value, resembling the overheated solar atmosphere, while the density profile near the surface may depart from the observations. Compared to the KVD models, the new RKD models can provide improved descriptions of gravitational equilibrium systems, especially for highly nonthermal cases and temperature profiles.https://doi.org/10.3847/1538-4357/ada76fCold dark matterSolar atmosphereNavarro–Frenk–White profileGalaxy dark matter halosGalaxy clustersGravitational fields
spellingShingle L.-N. Hau
C.-K. Chang
M. Lazar
S. Poedts
Boltzmann–Poisson Theory of Nonthermal Self-gravitating Gases, Cold Dark Matter, and Solar Atmosphere
The Astrophysical Journal
Cold dark matter
Solar atmosphere
Navarro–Frenk–White profile
Galaxy dark matter halos
Galaxy clusters
Gravitational fields
title Boltzmann–Poisson Theory of Nonthermal Self-gravitating Gases, Cold Dark Matter, and Solar Atmosphere
title_full Boltzmann–Poisson Theory of Nonthermal Self-gravitating Gases, Cold Dark Matter, and Solar Atmosphere
title_fullStr Boltzmann–Poisson Theory of Nonthermal Self-gravitating Gases, Cold Dark Matter, and Solar Atmosphere
title_full_unstemmed Boltzmann–Poisson Theory of Nonthermal Self-gravitating Gases, Cold Dark Matter, and Solar Atmosphere
title_short Boltzmann–Poisson Theory of Nonthermal Self-gravitating Gases, Cold Dark Matter, and Solar Atmosphere
title_sort boltzmann poisson theory of nonthermal self gravitating gases cold dark matter and solar atmosphere
topic Cold dark matter
Solar atmosphere
Navarro–Frenk–White profile
Galaxy dark matter halos
Galaxy clusters
Gravitational fields
url https://doi.org/10.3847/1538-4357/ada76f
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AT mlazar boltzmannpoissontheoryofnonthermalselfgravitatinggasescolddarkmatterandsolaratmosphere
AT spoedts boltzmannpoissontheoryofnonthermalselfgravitatinggasescolddarkmatterandsolaratmosphere