The narrow line emission region: photo ionized disk atmosphere or
illuminated face of the donor HZ?
1)Thermal and ionization balance Þ upper limit on the e density;
2)EM from line fluxes Þ lower limits on the e
density;
3)Hea line ratios and
UV photo excitation calculations Þ upper limits to the radius enclosing the region;
Confidence limits (90%) on density and location of
the narrow line
emission region, obtained from spectroscopic
analysis and modelling.
The limits shown correspond to O VII, and similar limits with N VI
and Ne IX can be set