Related papers: A Unified Computational Model for Solar and Stella…
From the Sun we know that coronal mass ejections (CMEs) are a transient phenomenon, often correlated with flares. They have an impact on solar mass- and angular momentum loss, and therefore solar evolution, and make a significant part of…
Numerical models of solar flares typically focus on the behaviour of directly-heated flare models, adopting magnetic field- aligned, plane-parallel methodologies. With high spatial- and spectral-resolution ground-based optical observations…
We analyze a grid of radiative hydrodynamic simulations of solar flares to study the energy balance and response of the atmosphere to nonthermal electron beam heating. The appearance of chromospheric bubbles is one of the most notable…
Energetic particles that undergo strong pitch-angle scattering and diffuse through a plasma containing strong compressible MHD turbulence undergo diffusion in momentum space with diffusion coefficient Dp. In this paper, the contribution of…
M-dwarf flares observed by the \textit{Transiting Exoplanet Survey Satellite} (\textit{TESS}) sometimes exhibit a "peak-bump" light-curve morphology, characterized by a secondary, gradual peak well after the main, impulsive peak. A similar…
This short paper reviews several recent key observations of the processes occurring in the lower atmosphere (chromosphere and photosphere) during flares. These are: evidence for compact and fragmentary structure in the flare chromosphere,…
In addition to well-known mechanisms of excitation of solar and stellar oscillations by turbulent convection and instabilities, the oscillations can be excited by an impulsive localized force caused by the energy release in solar and…
Impulsive solar energetic electrons are often observed in the interplanetary space near the Earth and have an attractive diagnostic potential for poorly understood solar flare acceleration processes. We investigate the transport of solar…
Solar CMEs and flares have a statistically well defined relation, with more energetic X-ray flares corresponding to faster and more massive CMEs. How this relation extends to more magnetically active stars is a subject of open research.…
The emphasis of observational and theoretical flare studies in the last decade or two has been on the flare corona, and attention has shifted substantially away from the flare's chromospheric aspects. However, although the pre-flare energy…
Observations of flare-heated electrons in the corona typically suggest confinement of electrons. The confinement mechanism, however, remains unclear. The transport of coronal hot electrons into ambient plasma was recently investigated by…
We investigate electron acceleration resulting from 3D magnetic reconnection between an emerging, twisted magnetic flux rope and a pre-existing weak, open magnetic field. We first follow the rise of an unstable, twisted flux tube with a…
During solar flares, a large flux of energetic electrons propagate from the tops of reconnecting magnetic flux tubes toward the lower atmosphere. Over the course of the electrons' transport, a co-spatial counter-streaming return current is…
During a solar flare, it is believed that reconnection takes place in the corona followed by fast energy transport to the chromosphere. The resulting intense heating strongly disturbs the chromospheric structure, and induces complex…
Several mechanisms have been proposed to account for the formation of solar prominences or filaments, among which direct injection and evaporation-condensation models are the two most popular ones. In the direct injection model, cold plasma…
High energy electrons carry much of a solar flare's energy. Therefore, understanding changes in electron beam distributions during their propagation is crucial. A key focus of this paper is how the co-spatial return current reduces the…
The solar corona is a template to understand stellar activity. The Sun is a moderately active star, and its corona differs from active stars: active stellar coronae have a double-peaked EM(T) with the hot peak at 8-20 MK, while the non…
This thesis strives to improve our understanding of solar activity, specifically the behaviour of solar flares and coronal mass ejections. An investigation into the hydrodynamic evolution of a confined solar flare was carried out using…
Using high time cadence images from the STEREO EUVI, COR1 and COR2 instruments, we derived detailed kinematics of the main acceleration stage for a sample of 95 CMEs in comparison with associated flares and filament eruptions. We found that…
This paper investigates the temporal evolution of temperature, emission measure, energy loss and velocity in a C-class solar flare from both an observational and theoretical perspective. The properties of the flare were derived by following…