X-rays as the dominant excitation mechanism of [Feii] and H 2 emission lines in active galaxies

We investigate the excitation mechanisms of near-infrared [Feii] and H 2 emission lines observed in active galactic nuclei (AGNs). We built a photoionization model grid considering a two-component continuum: one component accounts for the 'big bump' component peaking at 1Ryd and another re...

Descripción completa

Detalles Bibliográficos
Autores: Dors, Oli L., Jr., Riffel, Rogemar A., Cardaci, Monica V., Hägele, Guillermo F., Krabbe, Ángela C., Pérez Montero, Enrique, Rodrigues, Irapuan
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2012
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/425237
Acceso en línea:http://hdl.handle.net/10261/425237
Access Level:acceso abierto
Palabra clave:Galaxies: ISM
Galaxies: Seyfert
Infrared: galaxies.
Descripción
Sumario:We investigate the excitation mechanisms of near-infrared [Feii] and H 2 emission lines observed in active galactic nuclei (AGNs). We built a photoionization model grid considering a two-component continuum: one component 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 Seyert 2 Mrk1066 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 [Feii]λ 1.2570μm/Paβ and m/Brγ is well reproduced by our models, as are the relationships that involve the H 2 emission-line ratios observed in the spectroscopic data. We conclude that heating by X-rays produced by active nuclei can be considered a common and very important mechanism of excitation of [Feii] and H 2. © 2012 The Authors Monthly Notices of the Royal Astronomical Society © 2012 RAS.