Non-Equilibrium Processes in the Solar Corona, Transition Region, Flares, and Solar Wind \textit{(Invited Review)}

Abstract

We review the presence and signatures of the non-equilibrium processes, both non-Maxwellian distributions and non-equilibrium ionization, in the solar transition region, corona, solar wind, and flares. Basic properties of the non-Maxwellian distributions are described together with their influence on the heat flux as well as on the rates of individual collisional processes and the resulting optically thin synthetic spectra. Constraints on the presence of high-energy electrons from observations are reviewed, including positive detection of non-Maxwellian distributions in the solar corona, transition region, flares, and wind. Occurrence of non-equilibrium ionization is reviewed as well, especially in connection to hydrodynamic and generalized collisional-radiative modelling. Predicted spectroscopic signatures of non-equilibrium ionization depending on the assumed plasma conditions are summarized. Finally, we discuss the future remote-sensing instrumentation that can be used for detection of these non-equilibrium phenomena in various spectral ranges.

Solar Physics, accepted

References in corpus (38)

• Self-consistent Coronal Heating and Solar Wind Acceleration from Anisotropic Magnetohydrodynamic Turbulence
• Hot Explosions in the Cool Atmosphere of the Sun
• Radiative recombination data for modelling dynamic finite-density plasmas
• Resolving the electron temperature discrepancies in HII Regions and Planetary Nebulae: kappa-distributed electrons
• Evidence of Non-Thermal Particles in Coronal Loops Heated Impulsively by Nanoflares
• High precision density measurements in the solar corona: I. Analysis methods and results for Fe XII and Fe XIII
• Non-equilibrium hydrogen ionization in 2D simulations of the solar atmosphere
• Relations between concurrent hard X-ray sources in solar flares
• RHESSI Line and Continuum Observations of Super-hot Flare Plasma
• The Formation of Kappa-Distribution Accelerated Electron Populations in Solar Flares
• The Unresolved Fine Structure Resolved - IRIS observations of the Solar Transition Region
• On-Orbit Degradation of Solar Instruments
• Observations of Subarcsecond Bright Dots in the Transition Region above Sunspots with the Interface Region Imaging Spectrograph
• Why Is Non-thermal Line Broadening of Spectral Lines in The Lower Transition Region of the Sun Independent of Spatial Resolution?
• Particle acceleration and transport in reconnecting twisted loops in a stratified atmosphere
• Non-equilibrium of Ionization and the Detection of Hot Plasma in Nanoflare-heated Coronal Loops
• Kappa distribution and hard X-ray emission of solar flares
• KAPPA: A Package for Synthesis of optically thin spectra for the non-Maxwellian kappa-distributions based on the CHIANTI database
• Suprathermal Electrons in the Solar Corona: Can Nonlocal Transport Explain Heliospheric Charge States?
• Density diagnostics derived from the OIV and SIV intercombination lines observed by IRIS
• Misestimation of temperature when applying Maxwellian distributions to space plasmas described by kappa distributions
• EBIT Charge-Exchange Measurements and Astrophysical Applications
• A Quantitative Model of Energy Release and Heating by Time-dependent, Localized Reconnection in a Flare with a Thermal Loop-top X-ray Source
• The Origin of Non-Maxwellian Solar Wind Electron Velocity Distribution Function: Connection to Nanoflares in the Solar Corona
• A Steady-State Picture of Solar Wind Acceleration and Charge State Composition Derived from a Global Wave-Driven MHD Model
• Effect of collisions and magnetic convergence on electron acceleration and transport in reconnecting twisted solar flare loops
• Non-Gaussian Velocity Distributions in Solar Flares from Extreme Ultraviolet Lines: A Possible Diagnostic of Ion Acceleration
• Signatures of the non-Maxwellian $\kappa$-distributions in optically thin line spectra \subtitle{I. Theory and synthetic Fe IX--XIII spectra}
• Differential emission measure Analysis of a limb solar flare on 2012 July 19
• The Evolution of the EM Distribution in the Core of an Active Region
• Imaging and Spectroscopic Observations of a Transient Coronal Loop: Evidence for the Non-Maxwellian $\kappa$-Distributions
• Collisional and Radiative Processes in Optically Thin Plasmas
• Temperature dependent growth rates of the upper-hybrid waves and solar radio zebra patterns
• Dynamics of double layers, ion acceleration and heat flux suppression during solar flares
• Suprathermal electron distributions in the solar transition region
• RESIK observations of He-like Ar X-ray line emission in solar flares
• X-ray Flare Spectra from the DIOGENESS Spectrometer and its concept applied to ChemiX on the Interhelioprobe spacecraft
• Scaling of collision strengths for highly-excited states of ions of the H- and He-like sequences