We investigate the absolute calibration of the EUV Imaging Spectrometer (EIS) on Hinode by comparing EIS full-disk mosaics with irradiance observations from the EUV Variability Experiment on the Solar Dynamics Observatory. We also use extended observations of the quiet corona above the limb combined with a simple differential emission measure model to establish new effective area curves that incorporate information from the most recent atomic physics calculations. We find that changes to the EIS instrument sensitivity are a complex function of both time and wavelength. We find that the sensitivity is decaying exponentially with time and that the decay constants vary with wavelength. The EIS short wavelength channel shows significantly longer decay times than the long wavelength channel.
The Astrophysical Journal Supplement Series
- Pub Date:
- July 2014
- Sun: corona;
- Astrophysics - Solar and Stellar Astrophysics
- This is a draft. The paper has not been submitted yet. Comments are welcome! [replaced missing bib information on 10/22