The Unification of Radio-Loud AGN

  • C. M. Urry
  • Paolo Padovani
Conference paper
Part of the International Astronomical Union book series (IAUS, volume 175)


In a recent review paper we summarized the current status of unification of radio-loud AGN (Urry & Padovani 1995 PASP 107, 803), connecting high-luminosity (FR II) radio galaxies with quasars, and low-luminosity (FR I) radio galaxies with BL Lac objects. Unified schemes are motivated by the knowledge that AGN appearance depends strongly on orientation (Fig. 1): optical/UV light from the centers of many AGN is obscured by circumnuclear matter, and in radio-loud AGN, bipolar relativistic jets beam light along the jet axes. Understanding these radiation anisotropics allows us to unify apparently distinct classes of AGN that differ primarily because of orientation.


Black Hole Radio Source Radio Galaxy Central Black Hole Extragalactic Radio Source 
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Copyright information

© International Astronomical Union 1996

Authors and Affiliations

  • C. M. Urry
    • 1
  • Paolo Padovani
    • 2
  1. 1.Space Telescope Science InstituteBaltimoreUSA
  2. 2.Dipartimento di FisicaII Università di Roma “Tor Vergata”RomaItaly

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