Special issues No. 2,
Pages: 47-48,
https://doi.org/10.69646/15scslsa28
XV Serbian Conference on Spectral Line Shapes in Astrophysics
Published by: Astronomical Observatory Belgrade

We use a large sample of high-quality Type 1 active galactic nuclei (AGNs) spectra, taken from SDSS, to investigate the relative intensities among Fe II emission lines in the 4000-5600Å range. We perform the fitting procedure using a complex Fe II template made by modifying the Fe II template given in Kovačević et al.(2010).The new template includes more parameters of freedom for Fe II multiplets, thus enabling more sophisticated analysis of the complex Fe II features. The Fe II lines were divided into two large groups: consistent, those whose relative intensities are in accordance with theoretical calculations following their transition probabilities, and inconsistent, those whose observed relative intensities are significantly stronger than theoretically expected. We found that the strength of the inconsistent Fe II lines relative to the consistent ones are correlated with the line widths and Eddington ratio. They have similar relative intensities in the spectra with narrow Fe II lines and high Eddington ratio. As spectra have broader lines and a smaller Eddington ratio, the inconsistent Fe II lines tend to have smaller intensities relative to consistent Fe II lines. In the case of spectra with very broad lines, they disappear,while consistent Fe II lines could still be strong.