The standard solar flare model: reloaded!
Solar flares represent the most energetic explosions in our heliosphere and they emit copious amounts of electromagnetic radiation. The standard solar flare model in solar and high energy astrophysics textbooks, is a cartoon of all physical ingredients: magnetic fields that change connectivity, plasma dynamics, charged particle acceleration, and both thermal and non-thermal (e.g. bremsstrahlung) radiative processes. While these ingredients have been known from observations for a very long time, virtually all model efforts still fall into two categories: those handling the consequences of fast particle dynamics along individual field lines, and those modeling the thermal plasma in 2D or 3D, using a magnetohydrodynamic approach. Our proposal plans to finally bridge this gap, combining a multidimensional model for the thermal plasma with a field-line guided fast particle treatment. This should allow us to answer a number of outstanding questions from the standard flare model: (1) How are loop top and footpoint hard X-ray sources generated?; (2) What is the relation between the hard X-ray and soft X-ray emission, and does this generalize to flares beyond the solar case?; (3) Which physical mechanism drives the observationally established upflows of several hundred kilometers per second? Answering these will reload the standard model, and upgrade it from a cartoon to an actually self-consistent, simulated scenario, which we can observe synthetically and compare to real flares.