X-Ray Spectroscopy via Temporal Decomposition

Abstract We present a novel way to fit solar flare X-ray spectra that offers more sensitivity to physical flare parameters than traditional approaches to spectroscopy for certain types of flares. We decouple physically distinct emission types in solar flare X-ray spectra using timing behaviors, a technique we call temporal decomposition. By fitting time series to basis series across a time interval, we extract X-ray emission of distinct physical origins before any forward spectral modeling. We then perform spectroscopy on the original and time-decomposed spectra and find good agreement. In general, the time decomposition technique provides more precise results than those of traditional spectroscopy. We explain mathematically why the technique works using the multifractal formalism, and show that fractality is one way to choose appropriate light curves for this analysis. We speculate about applications to different wavelengths for solar data analysis, as well as applications to other physics subfields and domains.