SOLARNET Conference: The Many Scales of the Magnetic Sun

Probing the sub-structure of solar flare ribbons

Not scheduled

20m

Haus H, Telegrafenberg

Poster presentation 3) Energy and mass flow through the solar atmosphere – from solar campfires to CME (Observations and Theory) Energy and mass flow through the solar atmosphere – from solar campfires to CME (Observations and Theory)

Speaker

Malcolm Druett (KU Leuven)

Description

Solar flares are among the most spectacular and energetic phenomena in the solar system, and understanding their driving mechanisms is of paramount importance in solar physics. It is widely accepted that magnetic reconnection is the primary mechanism behind solar flares. This process allows for the conversion of magnetic energy into plasma energy, resulting in the acceleration of particles such as electrons and ions. These accelerated particles form electron beams that deposit energy into the coronal plasma locally, and also transfer energy globally when they impact the chromosphere. This global energy transfer is responsible for the characteristic ribbon-shaped emission of Hydrogen 656.3nm (Hα) observed across the Sun's surface during flares.

Recent advancements in observational technology, such as the high-resolution Swedish 1-m Solar Telescope (SST) and CRisp Imaging SpectroPolarimeter (CRISP), have enabled us to study the intricate substructures of these Hα ribbons in unprecedented detail. In particular, we have identified and analyzed small-scale substructures within the ribbons that we refer to as "riblets". By studying the statistical and kinematic properties of these riblets, we gain unique insight into the physical processes underlying electron beam energy deposition in the chromosphere.

In this work, we present our definition of riblets and a detailed analysis of their formation during an X-class solar flare observed on 10 June 2014. By examining the riblets at a resolution of 43 km per pixel and a cadence of 0.2 s, we are able to probe the microphysics of energy deposition in the chromosphere with unprecedented precision. Our analysis provides valuable constraints on theoretical models of electron beam physics, such as the 1D radiation hydrodynamic models HYDRO2GEN and RADYN. Ultimately, this work enhances our understanding of the complex interplay between magnetic fields, plasma, and particles in the Sun's atmosphere, and provides a foundation for further research into the physics of solar flares.