In this study, a refined approach for multicomponent fitting of active
galactic nuclei (AGN) spectra is presented utilizing the newly developed Python
code fantasy (fully automated python tool for AGN spectra analysis). AGN
spectra are modeled by simultaneously considering the underlying broken
power-law continuum, predefined emission line lists, and an Fe II model, which
is here extended to cover the wavelength range 3700 - 11000 A. The Fe II model,
founded solely on atomic data, effectively describes the extensive emission of
the complex iron ion in the vicinity of the Hγ and Hβ lines, as
well as near the Hα line, which was previously rarely studied. The
proposed spectral fitting approach is tested on a sample of high-quality AGN
spectra from the Sloan Digital Sky Survey (SDSS) Data Release 17. The results
indicate that when Fe II emission is present near Hβ, it is also detected
redward from Hα, potentially contaminating the broad Hα line
wings and thus affecting the measurements of its flux and width. The production
of Fe II emission is found to be strongly correlated with Eddington luminosity
and appears to be controlled by the similar mechanism as the hydrogen Balmer
lines. The study highlights the benefits of fitting AGN type 1 spectra with the
fantasy code, pointing that it may be used as a robust tool for analyzing a
large number of AGN spectra in the coming spectral surveys.Comment: Accepted in ApJ