Testing the AGN unified scheme for the most luminous 3CR radio galaxies and quasars

• Applicant: Privatdozent Dr. Martin Haas
• Subject Area: Astrophysics and Astronomy
• Term: from 2007 to 2011
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 58385755

• Final Report Year: 2011

Final Report Abstract

Observationally at least a dozen classes of active galactic nuclei (AGN) can be discerned. This diversity can be reduced to a few (if not a single) physically identical classes by means of unification schemes. The most common scheme is based on orientation of the axis-symmetrical objects: Their appearance depends on whether we see them nearly face-on (as quasars) or more edge-on (as radio galaxies). A check of this scheme requires observations of sufficiently isotropic, i.e. orientation-independent, quantities. Therefore we have performed and analysed mid-infrared (MIR) observations with the Spitzer Space Telescope: Photometry of a complete sample of 64 high-redshift 3CR sources and spectroscopy of a representative subset of 20 sources. The core question is how far the most luminous radio galaxies are intrinsically identical to quasars. The advantage of the luminous sample is that the disturbing effects of the host galaxies are presumably very small. Compared with optical and near-infrared observations the extinction is much lower at MIR wavelengths. The most important results of the MIR observations are: • Radio galaxies show significant absorption, consistent with the orientation-dependent AGN unification. • Both radio galaxies and quasars exhibit AGN-typical high-excitation MIR emission lines, and the strength of these lines is similar for radio galaxies and quasars, exactly as predicted by the orientation-dependent AGN unification. • By comparing our sample with less luminous AGN, we find luminosity-dependent differences (evolutionary effects), for which several explanations could be considered. The questions, which can be addresed with MIR observations, have been solved surprisingly well. We have been granted observations of the entire sample with the Herschel Space Observatory. This continuation will be supported by Deutsches Zentrum für Luft- und Raumfahrt (DLR).

Publications

• 2008, Radio Galaxies in the Chandra Era, Cambridge, USA. High redshift 3CR sources: cluster signatures aroung the z=1.5 quasar 3C270.1
  Heymann, F. et al.
  
• 2008, Radio Galaxies in the Chandra Era, Cambridge, USA. High redshift 3CR sources: Mid-infrared spectral energy distributions
  Willner, S. et al.
  
• Near- and Mid-Infrared Photometry of High-Redshift 3CR Sources. 2008, Astrophys. J. 688, 122
  Haas, M.; Willner, S. P.; Heymann, F.; Ashby, M. L. N.; Fazio, G. G.; Wilkes, B. J.; Chini, R.; Siebenmorgen, R.
  
• 2009, Chandra’s First Decade of Discovery, Boston, USA. Orientation Effects in the X-ray Properties of High-z 3CRR Quasars
  Wilkes, B. et al.
  
• Clustering of Red Galaxies around the z = 1.53 Quasar 3C 270.1. 2009, Astrophys. J. 695, 724
  Haas, M.; Willner, S. P.; Heymann, F.; Ashby, M. L. N.; Fazio, G. G.; Wilkes, B. J.; Chini, R.; Siebenmorgen, R., Stern D.
  
• Mid-infrared Spectroscopy of High-redshift 3CRR Sources. 2010, Astrophys. J. 717, 766
  Leipski, C.; Haas, M.; Willner, S. P.; Ashby, M. L. N.; Wilkes, B. J.; Fazio, G. G.; Antonucci, R.; Barthel, P.; Chini, R.; Siebenmorgen, R.; Ogle, P.; Heymann, F.
  
• 2011, AAS. Orientation Effects in the Spectral Energy Distributions of High-z 3CRR Sources Including New Far-IR Herschel Data
  Kuraszkiewicz, J. et al.
  
• 2011, AAS. Orientation Effects in the X-ray Properties of High-z 3CRR Quasars
  Wilkes, B. et al.
  
• Quantifying the Anisotropy in the Infrared Emission of Powerful Active Galactic Nuclei. 2011, Astrophys. J. 736, 26
  Hönig, S. F.; Leipski, C.; Antonucci, R.; Haas, M.