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Extragalactic radio source evolution under the dual-population unification scheme

C A Jackson·J V Wall
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Abstract

We show that a dual-population unification scheme provides a successful paradigm with which to describe the evolution and beaming of all bright extragalactic radio sources. The paradigm consists of two intrinsic radio-source populations, based on the two distinct radio-galaxy morphologies of Fanaroff-Riley classes I and II. These represent the `unbeamed' or `side-on' parent populations of steep radio spectra; the `beamed' source types including flat-spectrum quasars and BL Lac objects, arise through the random alignment of their radio-axis to our line-of-sight where Doppler-beaming of the relativistic radio jets produces highly anisotropic radio emission.

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C A Jackson, J V Wall. 1998-11-05. Extragalactic radio source evolution under the dual-population unification scheme. https://doi.org/10.1046/j.1365-8711.1999.02310.x

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