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1 - HISTORICAL BACKGROUND

Published online by Cambridge University Press:  05 June 2012

Ajit K. Kembhavi
Affiliation:
Inter-University Centre for Astronomy and Astrophysics (IUCAA), Pune, India
Jayant V. Narlikar
Affiliation:
Inter-University Centre for Astronomy and Astrophysics (IUCAA), Pune, India
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Summary

Introduction: the energy problem

The discovery of quasi-stellar objects (QSOs or quasars) in 1963 represents a landmark in observational astronomy. Thanks to a coordination between optical and radio astronomers, it was possible to discover a new and important class of astronomical objects. Because this text book is all about quasars and related phenomena, it will not be out of place to begin at the beginning of the subject and to review briefly how these remarkable objects were first discovered.

The science of radio astronomy really began after the end of World War II, when some of the scientists and engineers engaged in wartime radar projects used their know-how to follow up the pioneering works of Karl Jansky in the 1930s and Grote Reber in the early 1940s. Thus radio dishes and interferometers appeared in England and Australia, at Jodrell Bank, Cambridge, Sydney and Parkes.

The early observations revealed the existence of cosmic radio sources and by the mid- 1950s it became an accepted fact that radio galaxies exist. The nature of their radiation was non-thermal, and its polarization properties indicated that its origin lay in the synchrotron process. As we will discuss in Chapter 3, in this process radiation comes from electrons accelerated by a magnetic field. Thus a typical radio source has as its energy reservoir the dynamical energy of relativistic particles and magnetic field energy.

In 1958 Geoffrey Burbidge drew attention to the enormous size of this energy reservoir.

Type
Chapter
Information
Quasars and Active Galactic Nuclei
An Introduction
, pp. 1 - 11
Publisher: Cambridge University Press
Print publication year: 1999

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  • HISTORICAL BACKGROUND
  • Ajit K. Kembhavi, Inter-University Centre for Astronomy and Astrophysics (IUCAA), Pune, India, Jayant V. Narlikar, Inter-University Centre for Astronomy and Astrophysics (IUCAA), Pune, India
  • Book: Quasars and Active Galactic Nuclei
  • Online publication: 05 June 2012
  • Chapter DOI: https://doi.org/10.1017/CBO9781139174404.002
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  • HISTORICAL BACKGROUND
  • Ajit K. Kembhavi, Inter-University Centre for Astronomy and Astrophysics (IUCAA), Pune, India, Jayant V. Narlikar, Inter-University Centre for Astronomy and Astrophysics (IUCAA), Pune, India
  • Book: Quasars and Active Galactic Nuclei
  • Online publication: 05 June 2012
  • Chapter DOI: https://doi.org/10.1017/CBO9781139174404.002
Available formats
×

Save book to Google Drive

To save content items to your account, please confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account. Find out more about saving content to Google Drive.

  • HISTORICAL BACKGROUND
  • Ajit K. Kembhavi, Inter-University Centre for Astronomy and Astrophysics (IUCAA), Pune, India, Jayant V. Narlikar, Inter-University Centre for Astronomy and Astrophysics (IUCAA), Pune, India
  • Book: Quasars and Active Galactic Nuclei
  • Online publication: 05 June 2012
  • Chapter DOI: https://doi.org/10.1017/CBO9781139174404.002
Available formats
×