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The Nature of the Energy Source in Radio Galaxies and Active Galactic Nuclei

Published online by Cambridge University Press:  14 August 2015

F. Pacini  and
M. Salvati
F. Pacini
Affiliation:
Arcetri Astrophysical Observatory and University of Florence, Italy
M. Salvati
Affiliation:
Institute of Space Astrophysics CNR CNR Frascati, Italy

Extract

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For more than 20 years it has been known that extragalactic radio sources contain up to 1060–1062 ergs in the form of relativistic electrons and magnetic fields. One arrives at these figures if one assumes that the radio emission is due to the synchrotron process and the source contains an equal amount of energy in electrons and fields (Burbidge 1956). Any deviation from the postulated equipartition increases the energy required to account for the observed luminosities. Some authors believe that the real demands on the energy source may be still higher because of the probable presence of high energy protons. The ratio Ep/Ee is determined by the way in which particles gain and lose energy, and it is impossible to estimate it a priori. Observationally one has two conflicting lines of evidence: (a) in galactic cosmic rays one measures (Ep/Ee) ≃ 102; (b) in the Crab Nebula one infers (Ep/Ee) ≲ 1 (otherwise the dynamical pressure of the proton gas would cause a nebular expansion much faster than observed).

Type
Research Article
Information
Symposium - International Astronomical Union , Volume 97: Extragalactic Radio Sources , 1982 , pp. 247 - 253
Copyright
Copyright © Reidel 1982 

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