Abstract
The 3-D locations and volumes of X-ray emitting sources in the solar atmosphere are crucial to understanding the evolution of high energy processes in solar eruptive events. However to date, estimates of these properties have only ever been conducted in 2-D. Volume estimates of have relied on approximate area-to-volume scaling laws, while source locations have been inferred based on assumptions of the sources’ place within magnetic field structure of the standard flare model. In this presentation, we discuss recent and ongoing efforts to directly derive 3-D topologies of high-energy sources for the first time from stereoscopic solar X-ray and EUV observations. This is primarily enabled by the Spectrometer/Telescope for Imaging X-rays (STIX) and Extreme Ultraviolet Imager (EUI) onboard Solar Orbiter. We demonstrate that thermal X-ray sources can be characterised by applying an elliptical tie-pointing analysis to joint STIX and Hinode/XRT observations. We also explore the potential of full spatio-spectro-temporal reconstructions by combining STIX with ASO-S/HXI. Finally, we show how triangulation of EUV structures has helped us to understand electron acceleration in erupting CMEs. As such techniques are further developed and applied, they promise to improve our understanding of the evolution of solar eruptive events, specifically their energetics, cooling mechanisms, electron acceleration, and the spatial relationship between the hottest plasmas and magnetically connected structures such as ribbons and footpoints.