Fig. 3: Differential flux of negative ions from the surface.
From: Direct observations of negative ions on the Lunar surface by Chang'E-6
Top panel: negative hydrogen ion flux, bottom panel: negative oxygen ion flux. The vertical error bars represent 90% confidence intervals and the horizontal error bars represent the energy resolution of the instrument. Black data points are significantly different from zero, grey data points are not. Confidence intervals without a data point indicate that the data point is below the differential flux range shown. The dashed line corresponds to a 90% significance limit below which the differential flux cannot be distinguished from zero. The solid black line is an empirical fit of a log-normal function to the observed H− spectrum. The mean solar wind proton energy is indicated by the black arrow.
