Orateur
Description
Solar eruptions are initiated and develop in the solar corona and are one of the most extreme manifestation of the sun impulsive release of energy. Solar particles are accelerated during solar eruption. We observe their radiative signatures in the solar atmosphere over a large range of wavelengths from EUV to gamma rays and measure them in-situ in the heliosphere. Solar energetic particles provide a unique opportunity to study particle acceleration and transport processes in astrophysical plasmas. I will present a comprehensive overview of the current understanding of Solar Energetic Particles, focusing on their observational diagnostics and theoretical modeling.
I will first describe how complementary multi-wavelength and multi-messenger diagnostics offer powerful constraints on the physical processes governing particle acceleration, injection, and propagation. Then I will focus on the main physical mechanisms proposed to explain solar particle acceleration such as acceleration at CME-driven shocks, magnetic reconnection in solar flares, and stochastic acceleration in turbulent environments. I will highlight the strengths and limitations of existing models, as well as the challenges in reconciling them with the observations. Finally, while a wide range of observational diagnostics and theoretical modelling have provided valuable insights, they are often interpreted within simplified and/or localized frameworks. In many cases, the global dynamics of the eruptive event are not taken into account. This can lead to ambiguities or even misconceptions regarding the timing, location, and efficiency of particle acceleration and injection. I will discuss how developing multi-scale models to simulate the global context of solar eruptions is essential to interpret SEP observations and to go beyond our current understanding of their acceleration, injection and propagation.