Modeling the Daily Variations of the Coronal X-ray Spectral Irradiance with Two Temperatures and Two Emission Measures

The Miniature X-ray Solar Spectrometer (MinXSS-1) CubeSat observed solar X-rays between 0.5 and 10 keV. A two-temperature, two-emission measure model is fit to each daily averaged spectrum. These average temperatures emission measures are plotted against the corresponding 10.7 cm radio flux (F10.7) value a linear correlation found that we call Schwab Woods Mason (SWM) model. trends show one can estimate spectrum keV based on F10.7 measurement alone. cooler temperature component of this represents quiescent sun contribution spectra essentially independent activity, meaning accurately described by single (1.70 MK) regardless intensity only needs be adjusted for higher or lower intensity. warmer shown represent active region contributions varies 5 MK 6 MK. GOES XRS-B data 1-8 Angstroms used validate it ratio SWM irradiance close unity average. MinXSS-1 during conditions have very low counts beyond around 3 generate DAXSS at high spectral resolution with extended energy ranges fill in gaps measurements extend predictions back 1947.