SIMBAD references

We present the kinematical properties of the UV and optical Fe II emission gas based on the velocity shift and line width measurements of a sample of 223 Type 1 active galactic nuclei (AGNs) at 0.4 < z < 0.8. We find a strong correlation between the line widths of the UV and optical Fe II emission lines, indicating that both Fe II emission features arise from similar distances in the broad-line region (BLR). However, in detail we find differing trends, depending on the width of Fe II. While the velocity shifts and dispersions of the UV Fe II (Fe II_uv) and optical Fe II (Fe II_opt) emission lines are comparable to each other for AGNs with relatively narrow Fe II_opt line widths (i.e., FWHM < 3200 km s^–1; Group A), Fe II_opt is broader than Fe II_uv for AGNs with relatively broad Fe II_opt (i.e., FWHM > 3200 km s^–1; Group B). Fe II emission lines are on average narrower than Hβ and Mg II for Group A, indicating the Fe II emission region is further out in the BLR, while for Group B AGNs Fe II_opt is comparable to Hβ and broader than Mg II. While Fe II emission lines are on average redshifted (40 ± 141 km s^–1 and 182 ± 95 respectively for Fe II_uv and Fe II_opt), indicating inflow, the sample as a whole shows a large range of velocity shifts, suggesting the complex nature of the gas kinematics.