AAS 200th meeting, Albuquerque, NM, June 2002
Session 22. Extra Galactic Magnetic Fields: Their Origin and Manifestation through Structure of Quasars, Radio Lobes and within Clusters
Special Session Oral, Monday, June 3, 2002, 10:00-11:30am, La Cienega

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[22.03] The Origins and Consequences of Extra Galacitc Magnetic Fields

S.A. Colgate, H. Li (Los Alamos Nat. Lab), P.P. Kronberg (Los Alamos Nat. Lab & Univ. Toronto), Magnetized Universe Collaboration

The magnetic energy implied by the minimum energy analysis of the giant radio lobes as well by the Faraday rotation measurements of similar radio sources in clusters is so large, 1061 and 1060 ergs respectively compared to the binding energy of the galaxy itself 1058 ergs, and that of the galactic magnetic energy, ~1055 ergs, that the only feasible astrophysical source of this energy is the formation energy of the central black hole itself, 108 MO c2 = 2 x 1062 ergs. Furthermore the assumption of minimum energy of the Radio lobes implies equal enenergy in electrons of \gamma ~105 and therefore again ~1060 ergs in relativistic electrons per galaxy and protons perhaps more. These we associate with extra galactic cosmic rays whose total energy with the galactic spectral index of \Gamma = -2.7 also becomes >1060 ergs per intergalaxy volume. Finally we note that these energies are all large compared to the viral energy of the extra galactic baryonic matter, ~1012 M0 v100km/s2 ~1059 ergs per galaxy. To explain this we show how the formation energy of the BH may be converted to magnetic energy in an accretion disk dynamo where the magnetic flux generated by the dynamo is wrapped up into a force-free helix, the jet, and ejected, nearly mass-free, from the BH gravitational binding. The luminosity becomes the synchrotron radiation from the force-free, run-away current. Tearing mode reconnection allows flux conversion to the spheromak or radio lobe geometry and furthermore accelerates the electrons causing the synchrotron luminosity. Supported by the DOE.

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Bulletin of the American Astronomical Society, 34
© 2002. The American Astronomical Soceity.