Solar flares are fast increases in the X-ray flux. When they reach Earth, these energetic radiations ionize the atmosphere, increasing thus the electron density down to the lowest D-region of the ionosphere (60km). This, in turn, causes a greater absorption of the HF waves, which are frequency bands used by several actors like civil aviation and emergency services. Real-time detection of solar...
The Sun is a fascinating physics laboratory where periodically phases of strong activity and of quietness alternate during a eleven years cycle. The phase of strong activity is linked to the appearance of sunspots. These sunspots are cooled down regions of the sun and are the place of energetic events called solar eruptions.
Solar eruptions are major events corresponding either to solar...
La physique solaire a encore beaucoup de défis à relever, tels que l'origine de son cycle solaire de 11 ans, la formation de taches solaires et leur rôle sur l'établissement du cycle magnétique, ou le déclenchement des éruptions solaires et le chauffage de son atmosphère étendue. Pour étudier ces questions difficiles il est nécessaire de développer de nouveaux outils afin de les traiter comme...
The largest structures in the Universe to fully overcome cosmic expansion by their gravitational attraction are galaxy clusters. When they are still in their formation phase, they are called galaxy protoclusters and are expected to play an important role in star formation, giving rise to an epoch called the Cosmic Noon (cosmological redshift $z \sim 2-3$). My goal is to find precise...
The James Webb Space Telescope (JWST) has discovered a very surprising type of galaxy, a large population of compact red objects known as Little Red Dots (LRDs). To this day, this population remains misunderstood because of two opposing explanations: either they can be compact dusty star forming galaxies or Active Galactic Nucleus (AGNs). In both cases, the physics involved is very extreme,...
