Author name code: frogner ADS astronomy entries on 2022-09-14 author:Frogner, Lars ------------------------------------------------------------------------ Title: Accelerated particle beams in a 3D simulation of the quiet Sun Authors: Frogner, L.; Gudiksen, B. V.; Bakke, H. Bibcode: 2020A&A...643A..27F Altcode: 2020arXiv200514483F Context. Observational and theoretical evidence suggest that beams of accelerated particles are produced in flaring events of all sizes in the solar atmosphere, from X-class flares to nanoflares. Current models of these types of particles in flaring loops assume an isolated 1D atmosphere.
Aims: A more realistic environment for modelling accelerated particles can be provided by 3D radiative magnetohydrodynamics codes. Here, we present a simple model for particle acceleration and propagation in the context of a 3D simulation of the quiet solar atmosphere, spanning from the convection zone to the corona. We then examine the additional transport of energy introduced by the particle beams.
Methods: The locations of particle acceleration associated with magnetic reconnection were identified by detecting changes in magnetic topology. At each location, the parameters of the accelerated particle distribution were estimated from local conditions. The particle distributions were then propagated along the magnetic field, and the energy deposition due to Coulomb collisions with the ambient plasma was computed.
Results: We find that particle beams originate in extended acceleration regions that are distributed across the corona. Upon reaching the transition region, they converge and produce strands of intense heating that penetrate the chromosphere. Within these strands, beam heating consistently dominates conductive heating below the bottom of the transition region. This indicates that particle beams qualitatively alter the energy transport even outside of active regions. Title: Non-thermal electrons from solar nanoflares Authors: Bakke, Helle; Frogner, Lars; Gudiksen, Boris Vilhelm Bibcode: 2018arXiv181112404B Altcode: Context. We introduce a model for including accelerated particles in pure magnetohydrodynamics (MHD) simulations of the solar atmosphere. Aims. We show that the method is viable and produces results that enhance the realism of MHD simulations of the solar atmosphere. Methods. The acceleration of high-energy electrons in solar flares is an accepted fact, but is not included in the most advanced 3D simulations of the solar atmosphere. The effect of the acceleration is not known, and here we introduce a simple method to account for the ability of the accelerated electrons to move energy from the reconnection sites and into the dense transition zone and chromosphere. Results. The method was only run for a short time and with low reconnection energies, but this showed that the reconnection process itself changes, and that there is a clear effect on the observables at the impact sites of the accelerated electrons. Further work will investigate the effect on the reconnection sites and the impact sites in detail. Title: Non-thermal electrons from solar nanoflares. In a 3D radiative MHD simulation Authors: Bakke, H.; Frogner, L.; Gudiksen, B. V. Bibcode: 2018A&A...620L...5B Altcode: Context. We introduce a model for including accelerated particles in pure magnetohydrodynamics (MHD) simulations of the solar atmosphere.
Aims: We show that the method is viable and produces results that enhance the realism of MHD simulations of the solar atmosphere.
Methods: The acceleration of high-energy electrons in solar flares is an accepted fact, but is not included in the most advanced 3D simulations of the solar atmosphere. The effect of the acceleration is not known, and here we introduce a simple method to account for the ability of the accelerated electrons to move energy from the reconnection sites and into the dense transition zone and chromosphere.
Results: The method was only run for a short time and with low reconnection energies, but this showed that the reconnection process itself changes, and that there is a clear effect on the observables at the impact sites of the accelerated electrons. Further work will investigate the effect on the reconnection sites and the impact sites in detail.