Improving the Spectral Resolution and Wavelength Scale of SDO/EVE MEGS-A Flare Observations

Abstract

The Extreme ultraviolet Variability Experiment (EVE) is one of three instruments onboard the Solar Dynamics Observatory (SDO). This paper focuses on using the “A” channel on the Multiple EUV Grating Spectrographs (MEGS-A) on EVE, which measures wavelengths of 5 – 37 nm, to improve the wavelength scale accuracy and spectral resolution during solar flares. EVE’s least processed (Level 0B) data product is used to create updated wavelength scales that are shown, through this analysis, to make more precise spectral measurements compared to EVE Level 2 data. An X2.2 class flare that occurred on 15 February 2011, SOL2011-02-15T0156, was used to derive the pixel-to-wavelength scales. An improvement range of 5.21% to 11.35% was found in the emission line widths. In the future, these measurements can be used for improved Doppler velocity calculations of the accelerated plasma of various temperatures during solar flares.