Solar Flare Soft X-Ray Time Series Spectrum Reconstruction

Solar flares are magnetic reconnection events resulting in sudden bursts of electromagnetic energy, particle acceleration, and hot plasma heated to over 10 MK. Hot solar flare plasma generates copious soft X-rays. Hence, spectral soft X-ray measurements provide great constraints on flare plasma temperature and dynamics. Flare observations from Low-Earth orbiting satellites like the first Miniature X-ray Solar Spectrometer (MinXSS-1) CubeSat can be occulted for 30 minutes of the 90 minute orbit, missing vital portions of the temporal evolution of the spectrum and plasma. In this project, the eclipsed MinXSS-1 spatially integrated spectra from 0.8 - 15 keV is reconstructed using non-oculted data by fitting an empirical piecewise temporal-spectral function consisting of Gaussian, Lorentian, and polynomial components. This automated pro- cedure fits the original data and adds synthetic data points to the eclipse period in the temporal profile, which can be used to reconstruct the spectral profile for energy range specified in the time series. At both points of egress and ingress there are larger decreases in the low energy (< 3 keV) soft X-ray flux due to absorption by nitrogen and oxygen in Earth’s atmosphere. Results from this project could be used in future projects focusing on exoplanet atmospheres and models of flare plasma evolution.