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Record 1 of 18622
The Invariant Twist of Magnetic Fields in the Relativistic Jets of Active Galactic Nuclei
Author and Affiliation:
Contopoulos, Ioannis
Christodoulou, Dimitris M.
Kazanas, Demosthenes(NASA Goddard Space Flight Center, Greenbelt, MD, United States)
Gabuzda, Denise C.
Abstract: The origin of cosmic magnetic (B) fields remains an open question. It is generally believed that very weak primordial B fields are amplified by dynamo processes, but it appears unlikely that the amplification proceeds fast enough to account for the fields presently observed in galaxies and galaxy clusters. In an alternative scenario, cosmic B fields are generated near the inner edges of accretion disks in Active Galactic Nuclei (AGNs) by azimuthal electric currents due to the difference between the plasma electron and ion velocities that arises when the electrons are retarded by interactions with photons. While dynamo processes show no preference for the polarity of the (presumably random) seed field that they amplify, this alternative mechanism uniquely relates the polarity of the poloidal B field to the angular velocity of the accretion disk, resulting in a unique direction for the toroidal B field induced by disk rotation. Observations of the toroidal fields of 29 AGN jets revealed by parsec-scale Faraday rotation measurements show a clear asymmetry that is consistent with this model, with the probability that this asymmetry came about by chance being less than 1 %. This lends support to the hypothesis that the Universe is seeded by B fields that are generated in AGN via this mechanism
Publication Date: Jan 01, 2009
Document ID:
20090032048
(Acquired Sep 09, 2009)
Subject Category: ASTRONOMY
Document Type: Preprint
Financial Sponsor: NASA Goddard Space Flight Center; Greenbelt, MD, United States
Organization Source: NASA Goddard Space Flight Center; Greenbelt, MD, United States
Description: 1p; In English
Distribution Limits: Unclassified; Publicly available; Unlimited
Rights: Copyright
NASA Terms: ACTIVE GALACTIC NUCLEI; INTERSTELLAR MAGNETIC FIELDS; ANGULAR VELOCITY; ELECTRON BEAMS; VELOCITY DISTRIBUTION; GALACTIC CLUSTERS; PROBABILITY THEORY; TOROIDAL PLASMAS
Miscellaneous Notes: Submitted to Astrophysical Journal Letters for publication
Availability Source: Other Sources
Availability Notes: Abstract Only
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