Published in New Astron.Rev. 46 (2002) 121-134
astro-ph/9911056

For a PDF version of the article, click here.

THE GASEOUS ENVIRONMENTS OF RADIO GALAXIES

D.M. Worrall 1


Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138, USA
&
Department of Physics, University of Bristol, Tyndall Avenue, Bristol BS8 1TL, UK


Key words: Radio continuum: Galaxies; X-rays: Galaxies: Clusters


Abstract. X-ray emission traces the gaseous environments of radio sources. The medium must be present for jet confinement, but what are its influence on jet fuelling, dynamics, propagation, and disruption? The observational situation is both complicated and enriched by radio sources being multi-component X-ray emitters, with several possible regions of non-thermal emission. Recent work, primarily based on sensitive ROSAT pointings, is used to contrast the X-ray emission and environments of radio sources with (a) low power, (b) high power at high redshift, (c) high power at lower redshift, and (d) GHz peaked spectrum emission. The trends in external gas density and pressure near extended radio structures are reviewed. Imminently-available X-ray measurements with vastly improved resolution and sensitivity have great potential for resolving many open issues.


Table of Contents

INTRODUCTION

MULTI-COMPONENT X-RAY EMISSION
Cygnus A
Observational Biases

NON-GASEOUS X-RAY EMISSION
Central Engine
Beamed X-ray Emission
Non-thermal emission components away from the core

THE GASEOUS X-RAY-EMITTING MEDIUM
Questions and Timescales
The Evidence

THE NEAR FUTURE

SUMMARY

REFERENCES



1 E-mail: d.worrall@bristol.ac.uk

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