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The radio–optical correlation in steep-spectrum quasars |
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| Authors: | Stephen Serjeant Steve Rawlings Stephen J Maddox Joanne C Baker Dave Clements Mark Lacy & Per B Lilje |
| Institution: | Astrophysics Department, Blackett Labs., Imperial College London, Prince Consort Road, London SW7 2BZ,;Astrophysics, Department of Physics, University of Oxford, Keble Road, Oxford OX1 3RH,;Royal Greenwich Observatory, Madingley Road, Cambridge CB3 0EZ,;Mullard Radio Astronomy Observatory, Cavendish Laboratory, Madingley Road, Cambridge CB3 0HE,;European Southern Observatory, Karl-Schwarzschild-Strasse 2, D-85748 Garching-bei-München, Germany,;Institute of Theoretical Astrophysics, University of Oslo, PO Box 1029 Blindern, N-0315 Oslo, Norway |
| Abstract: | Using complete samples of steep-spectrum quasars, we present evidence for a correlation between radio and optical luminosity which is not caused by selection effects, nor caused by an orientation dependence (such as relativistic beaming), nor a by-product of cosmic evolution. We argue that this rules out models of jet formation in which there are no parameters in common with the production of the optical continuum. This is arguably the most direct evidence to date for a close link between accretion on to a black hole and the fuelling of relativistic jets. The correlation also provides a natural explanation for the presence of aligned optical/radio structures in only the most radio-luminous high-redshift galaxies. |
| Keywords: | accretion accretion discs black hole physics galaxies: active galaxies: jets quasars: general |