Fe II template - download
Here you may download Fe II template (λλ 4000-5400 Å) for different Doppler widths of Fe II lines, starting with 700 km/s, until 2800 km/s, with step of 100 km/s.
These templates are obtained using the procedure described in paper Kovacevic, et. al, 2010, ApJS, 189, 15K, arXiv:1004.2212. The relative intensities of the lines are calculated by formula (see here) for T=9900 K. The shift of the Fe II lines is taken to be 0 km/s.
Fe II template - Download
In zipped folder there are several folders (700FeII, 800FeII, 900FeII,...2800FeII). In each of them there is Fe II template in form of spectrum - for specific Doppler width. fe_f.txt is sum of all lines from F group, fe_s.txt, fe_g.txt and fe_p.txt are the same of the S, G and P line groups, and fe_IZw1.txt are the lines obtained from I Zw 1 object.
To fit Fe II lines in some observed spectrum you need to:
1) estimate which Doppler width gives the best fit of observed Fe II lines (all Fe II lines from template should have the same width in one object).
2) fit the intensity: multiply each of files (fe_f, fe_s, fe_g, fe_p, fe_IZw1) with different parameter of intensity (5 parameters of intensity).
3) find the shift of Fe II lines (which is also the same for all Fe II lines from template).
For more precise fit, the temperature and width should be also free parameters.
Zipped folder also contains one more folder (FeII_rel_int), with only relative intensities of the Fe II lines within the line groups. This may be used for more precise fitting, since the width is also free parameter. Namely, the line intensities should be convoluted with Gaussians (with the same shift and width). Than, the spectra should be fitted with 7 free parameters: intensities for each line group (5), width and shift.
Typical examples of the Fe II template
Figure 1. The Fe II lines with Doppler width: ∼870 km/s (see fit parameters).
Figure 2. The Fe II lines with Doppler width: ∼1300 km/s (see fit parameters).
Figure 3. The Fe II lines with Doppler width: ∼1550 km/s (see fit parameters).
Figure 4. The Fe II lines with Doppler width: ∼2800 km/s (see fit parameters).