Published in Triennial Issue: Astronomy and Earth Science. Papers of a Theme compiled and edited by J. M. T. Thompson. Roy Soc of London Phil Tr A, vol. 360, Issue 1801, pp.2725-2740, 2002.
astro-ph/0208039

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VIOLENCE IN THE HEARTS OF GALAXIES - ABERRATION OR ADOLESCENCE?

C.G. Mundell


Astrophysics Research Institute, Liverpool John Moores University, Twelve Quays House, Egerton Wharf, Birkenhead, CH41 1LD, UK


Abstract. Violent activity in the nuclei of galaxies has long been considered a curiosity in its own right; manifestations of this phenomenon include distant quasars in the early Universe and comparatively nearby Seyfert galaxies, both thought to be powered by the release of gravitational potential energy as material from the host galaxy accretes onto a central supermassive black hole (SMBH). Traditionally, the broader study of the formation, structure and evolution of galaxies has largely excluded active galactic nuclei. Recently however, this situation has changed dramatically, both observationally and theoretically, with the realisation that the growth and influence of the SMBH, the origin and development of galaxies and nuclear activity at different epochs in the Universe may be intimately related. The most spectacular fireworks seen in distant quasars, may be relatively easy to explain since the era of greatest quasar activity seems to coincide with turbulent dynamics at the epoch of galaxy formation in the young, gas-rich Universe. Ubiquitous black holes are believed to be a legacy of this violent birth. Alternatively, black holes may be the seeds which drive galaxy formation in the first place. Closer to home, and hence more recently in the history of the Universe, a fraction of comparatively ordinary galaxies, similar to our own, have re-ignited their central engines, albeit at a lower level of activity. Since these galaxies are more established than their younger and more distant counterparts, the activity here is all the more puzzling. Whatever the mechanisms involved, they are likely to play an important role in galaxy evolution. I review the intriguing evidence for causal links between supermassive black holes, nuclear activity and the formation and evolution of galaxies, and describe opportunities for testing these relationships using the next generation of earth-bound and space-borne astronomical facilities.


Key words: Black holes; AGN; quasars; galaxy evolution


Table of Contents

INTRODUCTION

THE EARLY STUDIES OF ACTIVE GALACTIC NUCLEI

AGN ORIENTATION - LOOKING AT IT FROM ALL ANGLES
Too fast to believe - the remarkable jets in radio-loud AGN
Obscuring-Doughnuts in Radio-Quiet AGN
Further unification?

SEARCHING FOR SUPERMASSIVE BLACK HOLES
Quasar lifetimes and the black hole legacy
Irresistible black holes - dynamics of gas and stars

BLACK HOLE DEMOGRAPHICS - THE HOST GALAXY CONNECTION

AGN AND THEIR ENVIRONMENT
The violent early Universe
Re-activating dormant black holes in nearby galaxies

UNANSWERED QUESTIONS AND PROSPECTS FOR THE FUTURE

REFERENCES

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