Figure 15 shows a comparison
of the emission spectrum at densities of 10 cm
(panel a)
and 10
cm
(panel b) due to oxygen in the
0.5-1 keV energy range. The ionization parameter is log(
)=2 and the
temperature is 10
K. In the high density case the
ratio of continuum to line emission is reduced, and
the ratios of the He-like lines is changed from the familiar low-density
case in which the forbidden/intercombination line ratio is large
at low density to values
1 at high density.