Understanding Heating Properties in Hot and Warm Active Region Loops through Hydrodynamics and Forward Modeling

Abstract:

While it is generally agreed that the energy to power the multi-million-degree corona is contained in the complex solar magnetic field, the processes behind how this energy is transferred from the stressed magnetic field to the coronal plasma remain poorly understood. Active region observations from a number of solar observatories have shown that short, compact loops near the center of the active region are "hot," sometimes exceeding temperatures of 4 MK, and are consistent with steady heating, while long loops closer to the periphery of the active region are significantly cooler (around 1 MK) and may be powered by more intermittent heating. In this poster, we use a field-aligned hydrodynamic model, combined with loop properties constrained from observations and forward modeling, to better understand the heating properties across the active region. Specifically, we use the HYDRAD code to survey an array of heating parameters, from impulsive heating to thermal non-equilibrium induced by highly-stratified, localized foot point heating for a selection of loop geometries derived from field extrapolations. We then forward model spectroscopic observations from the EUV Imaging Spectrometer instrument onboard Hinode as well as narrow-band imaging observations from the Atmospheric Imaging Assembly onboard the Solar Dynamics Observatory, in order to make comparisons between observed loops and our models and thus constrain the parameter space of heating scenarios. In doing so, we gain insight into both how different types of loops are heated and how heating properties vary across the active region.