Description
Radiation remains the primary vector by which the properties of solar plasma can be investigated. Atomic spectral lines, often forming in thin atmospheric layers, offer a powerful mechanism to probe the solar atmosphere, in particular its outer layers where conditions are typically outside of local thermodynamic equilibrium. Synthesising the radiation produced by numerical models also provides an essential lens through which to compare models and observations. Isolated solar structures such as filaments and prominences are of particular interest due to the complexity of spectral line formation within them and the diagnostic window this provides onto their formation and stability.
In recent years, magnetohydrodynamic models of these isolated structures have become significantly more advanced, whilst radiative treatments have primarily remained the same. We have recently introduced the DexRT code: a novel approach to multidimensional non-equilibrium radiative transfer using a technique termed radiance cascades to efficiently treat problems with intertangled layers of optically thin and thick material – a regime where current approaches can fail with dramatic so-called ray effects. Here, I will present spectra from a variety of lines synthesised from detailed multidimensional magnetohydrodynamic models. I will also discuss the importance of considering both detailed radiative transfer and viewing angle effects when making predictions and comparisons to observations.
