Abstract
We investigate the nature of the emission lines spectrum of ions of the iron group, such as ScII, CrII, TiII and VII, observed in the so-called strontium filament found in the ejecta of Carinae. We calculate the atomic parameters for these systems and model the spectrum. We use the theoretical and observed spectrum to investigate the physical condition of the strontium filament and the excitation mechanisms of the lines observed. We use the line intensity ratios to diagnostic temperature, electronic density and radiation field, but the combined contributions of collisional excitation and fluorescence make spectral diagnostics much more difficult than with traditional collisionally excited lines. Once the temperature and density are known, we can calculate the abundances of the elements in the nebula.
