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Paper: |
Low-ionization lines in the Broad Line Region of Active Galactic Nuclei |
Volume: |
290, Active Galactic Nuclei: from Central Engine to Host Galaxy |
Page: |
245 |
Authors: |
RodrÃguez-Ardila, A.; Viegas, S. M.; Pastoriza, M. |
Abstract: |
Near-infrared spectroscopy is used to study the physical conditions and excitation mechanisms of the low-ionization species such as FeII and OI, emitted by the BLR. Primary cascade lines of FeII arising from the decay of upper levels pumped by Ly-alpha fluorescence are resolved and identified, for the first time, in AGNs. We show that the FeII lines located at 0.999, 1.050, 1.086 and 1.112 microns are the strongest FeII lines in the 0.8-2.4 micron interval. A combination of Ly-alpha fluorescence and collisional excitation are found to be the main contributors. For OI, we found that contrary to the general believed, Ly-beta fluorescence is not the dominant mechanism responsible for the formation of its permitted lines. |
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