| Presentation Title: | Exploring the effects of deep heating of the solar chromosphere during flares
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| Author(s): | Graham S. Kerr,
Adam F. Kowalski,
Joel C. Allred |
Abstract:
Radiation hydrodynamic (RHD) modelling of solar flares using standard nonthermal electron beams typically heat the mid-upper chromosphere, and have been largely successful in reproducing the broadly observed features. However, with high spatial and spectral resolution afforded by modern observatories (both ground and space-based, i.e. IRIS) it is clear that there are details of flare emission that these RHD models have been unable to explain. There are hints that heating to greater depths than standard electron beams can achieve are required. Here we explore deep heating of the solar chromosphere in two ways, and discuss the impacts on the resulting synthetic spectra and continua, with particular focus on line widths, that have been observed to be extremely broad in observations. First, we produce a set of adhoc models with a range of temperature gradients between the height of chromospheric condensations and the temperature minimum region. Second, we explore a particular case of an electron beam driven flare in which re-acceleration of particles results in a harder, more deeply penetrating energy spectra. Lines relevant for both IRIS (Mg II h & k, Mg II subordinate, O I, and C II) as well as ground based observatories (H Balmer series, Ca II H, Ca II 8542A) are explored.