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Evolution of Powerful Extended Radio Sources: Implications for Cosmology and Cosmogony

Published online by Cambridge University Press:  25 May 2016

R. A. Daly
R. A. Daly*
Affiliation:
Princeton University – Department of Physics Princeton, NJ 08544 – USA

Abstract

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Powerful extended radio sources are observed out to relatively large redshift. They may be used to study the properties and redshift evolution of the gaseous environment in the vicinity of each source, the active galactic nucleus (AGN), and the source size. This information may then be used to study and constrain cosmological and cosmogonical models. It is interesting to note that the rate of change of quantities with redshift allows constraints to be placed on global cosmological parameters and on models of structure formation and evolution that are completely independent of those inferred using the cosmic microwave background or local dynamical studies, and thus provide an important complement to these studies. The method does require that we understand the physics of the sources well enough to account for intrinsic source evolution. The physics of powerful extended radio sources that propagate supersonically appears to be relatively straight-forward. We have used the radio properties of the sources to deduce the ambient gas density, the beam power of the AGN, the characteristic time a particular AGN is on, and a characteristic source size that allows the sources to be used to probe global cosmological parameters. We plan to use the radio properties of the sources to deduce the ambient gas temperature, which will be combined with the ambient gas density to constrain cosmogonical models, that is, models of structure formation and evolution.

Type
Radio Sources and their Environment
Information
Symposium - International Astronomical Union , Volume 175: Extragalactic Radio Sources , 1996 , pp. 319 - 320
Copyright
Copyright © Kluwer 1996 

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