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arXiv · 1201.4046

X-rays as dominant excitation mechanism of [Fe ii] and H2 emission lines in active galaxies

Oli L. Dors Jr·Rogemar A. Riffel·Monica V. Cardaci·Guillermo F. Hagele·Angela C. Krabbe·Enrique Perez-Montero·Irapuan Rodrigues
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Abstract

We investigate the excitation mechanisms of near-infrared [Fe ii] and H2 emission lines observed in Active Galactic Nuclei (AGNs). We built a photoionization model grid considering a two-component continuum, one accounts for the Big Bump component peaking at 1Ryd and another represents the X-ray source that dominates the continuum emission at high energies. Photoionization models considering as ionizing source a spectral energy distribution obtained from photometric data of the Sy 2 Mrk 1066 taken from the literature were considered. Results of these models were compared with a large sample of observational long-slit and Integral field Unit (IFU) spectroscopy data of the nuclear region for a sample of active objects. We found that the correlation between the observational [Fe ii]λ1.2570 μm/Paβ vs. H2λ2.1218 μm/Brγ is well reproduced by our models as well as the relationships that involve the H2 emission line ratios observed in the spectroscopic data.We conclude that the heating by X-rays produced by active nuclei can be considered a common and very important mechanism of excitation of [Fe ii] and H2.

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Oli L. Dors Jr, Rogemar A. Riffel, Monica V. Cardaci, Guillermo F. Hagele, Angela C. Krabbe, Enrique Perez-Montero, Irapuan Rodrigues. 2012-01-19. X-rays as dominant excitation mechanism of [Fe ii] and H2 emission lines in active galaxies. https://doi.org/10.1111/j.1365-2966.2012.20600.x

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