Astronomy and Astrophysics
Aims: We investigate whether the properties of core ERQ fit the AGN orientation-based unification scenario.
Methods: We revised the general UV and optical emission line properties of core ERQ in the context of the orientation-based scenario. We used diagnostic diagrams based on UV emission line ratios and UV-to-optical line kinematic information to compare the physical and kinematic gas properties of core ERQ with those of other luminous narrow- and broad-line AGN. In particular, we provide a revised comparison of the [OIII] kinematics in 21 core ERQ (20 from Perrotta et al. 2019, MNRAS, 488, 4126 and SDSS J171420.38+414815.7, based on GTC EMIR near-infrared spectroscopy) with other samples of quasars with matching luminosity with the aim of evaluating whether core ERQ host the most extreme [OIII] outflows.
Results: The UV line ratios suggest that the physical properties (e.g., density and metallicity) of the ionised gas in core ERQ are similar to those observed in the broad-line region of blue nitrogen-loud quasars. The [OIII] outflow velocities of core ERQ are on average consistent with those of very luminous blue type 1 quasars, although extreme outflows are much more frequent in core ERQ. These similarities can be explained in the context of the AGN unification model under the assumption that core ERQ are viewed with an intermediate orientation between type 2 (edge-on) and type 1 (face-on) quasars.
Conclusions: We propose that core ERQ are very luminous but otherwise normal quasars viewed at an intermediate orientation. This orientation allows a direct view of the outer part of the large broad-line region from which core ERQ UV line emission originates; the extreme [OIII] outflow velocities are instead a consequence of the very high luminosity of core ERQ.
El Proyecto se estructura en dos partes, diferenciadas pero complementarias: morfología y dinámica. El estudio detallado de la morfología de la Vía Láctea pretende proveer una base de datos de distribución estelar en las regiones más alejadas y extintas de nuestra Galaxia, mediante el desarrollo de modelos semiempíricos a partir de la información