Extended Data Fig. 2: Example spectra from the Photoelectron Spectrometer.
From: Earth’s ambipolar electrostatic field and its role in ion escape to space
Data calibrated but uncorrected for spacecraft potential. a, PES Scan 72 showing standard resolution (black) and high resolution (red). b, PES Scan 72 zoomed in to the He-II photopeaks showing a gaussian fit (blue) to the primary N2 A2Πu dominated photopeak. c,d, The same for PES Scan 38.
