Boltzmann–Poisson Theory of Nonthermal Self-gravitating Gases, Cold Dark Matter, and Solar Atmosphere
Year: 2025
Type: article
Abstract: 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 κ —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 κ > 0 and κ < 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 ( κ ~ 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.
Source: The Astrophysical Journal
Authors: L.-N. Hau, C.-K. Chang, M. Lazar, S. Poedts
Language: English
Subfield: Statistical and Nonlinear Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $4,499
Awards: G1394250481, New theory and applications with the regularized Kappa-distribution, G2348175834, Understanding the solar radio emission processes from the Sun to EarthAcronym: UnderRadioSun, G4543786493, Impact of Advanced Multi-Scale Ensemble Data Assimilation on Severe and High-Impact Weather Prediction in Taiwan( II ), G6180803798, G6513226023, G8301932736, G8863810249
OpenAlex ID: W4407827650