Deconstructing the narrow-line region of the nearest obscured quasar
We study the physical and kinematic properties of the narrow-line region (NLR) of the nearest obscured quasar MRK 477 (z = 0.037), using optical and near-infrared (NIR) spectroscopy. About 100 emission lines are identified in the optical+NIR spectrum (90 in the optical), including several narrow opt...
| Autores: | , , , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2015 |
| País: | España |
| Institución: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repositorio: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:digital.csic.es:10261/388762 |
| Acceso en línea: | http://hdl.handle.net/10261/388762 |
| Access Level: | acceso abierto |
| Palabra clave: | Galaxies: active Quasars: emission lines Quasars: general Quasars: individual: MRK 477 |
| Sumario: | We study the physical and kinematic properties of the narrow-line region (NLR) of the nearest obscured quasar MRK 477 (z = 0.037), using optical and near-infrared (NIR) spectroscopy. About 100 emission lines are identified in the optical+NIR spectrum (90 in the optical), including several narrow optical Fe lines. To our knowledge, this is the first type 2 active galactic nucleus (AGN) with such a detection. The Fe lines can be explained as the natural emission from theNLRphotoionized by theAGN. Coronal line emission can only be confirmed in the NIR spectrum. As in many other AGNs, a significant correlation is found between the lines' full width at half-maximum and the critical density log(n).We propose that it is caused by the outflow. This could be the case in other AGNs. The nuclear jet-induced ionized outflow has been kinematically isolated in many emission lines covering a broad range of ionization potentials and critical densities. It is concentrated within R ~few×100 pc from the central engine. The outflowing gas is denser (n ≳ 8000 cm) than the ambient non-perturbed gas (n ~few× 400-630 cm). This could be due to the compression effect of the jet-induced shocks. Alternatively, we propose that the outflow has been triggered by the jet at R ≲ 220 pc (possibly at ≲ 30 pc), and we trace how the impact weakens as it propagates outwards following the radiation-pressure-dominated density gradient. The different kinematic behaviour of [Fe II] λ1.644 μm suggests that its emission is enhanced by shocks induced by the nuclear outflow/jet and is preferentially emitted at a different, less reddened spatial location. © 2015 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society. |
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