Dominance of outflowing electric currents on decaparsec to kiloparsec scales in extragalactic jets

Abstract

Helical magnetic fields embedded in the jets of active galactic nuclei (AGNs) are required by the broad range of theoretical models that advocate for electromagnetic launching of the jets. In most models, the direction of the magnetic field is random, but if the axial field is generated by a Cosmic Battery generated by current in the direction of rotation in the accretion disk, there is a correlation between the directions of the spin of the AGN accretion disk and of the axial field, which leads to a specific direction for the axial electric current, azimuthal magnetic field, and the resulting observed transverse Faraday-rotation (FR) gradient across the jet, due to the systematic change in the line-of-sight magnetic field. We consider new observational evidence for the presence of a nested helical magnetic-field structure such as would be brought about by the operation of the Cosmic Battery, and make predictions about the expected behavior of transverse FR gradients observed on decaparsec and kiloparsec scales. The collected results can be understood if the dominant azimuthal field on parsec scales corresponds to an axial electric current flowing inward along the jet, whereas the (weaker) dominant azimuthal field on kiloparsec scales corresponds to a outward-flowing current in the outer sheath of the jet and/or an extended disk wind.

arXiv comment12 pages, 4 figures, 1 table, accepted for publication in Astronomy & Astrophysics

References in corpus (47)

• Giant Gamma-ray Bubbles from Fermi-LAT: AGN Activity or Bipolar Galactic Wind?
• Cluster Magnetic Fields
• On the Origin of Cosmic Magnetic Fields
• The Coma cluster magnetic field from Faraday rotation measures
• The Spectrum and Morphology of the Fermi Bubbles
• Deriving global structure of the Galactic Magnetic Field from Faraday Rotation Measures of extragalactic sources
• Magnetic Fields and Faraday Rotation in Clusters of Galaxies
• MOJAVE: Monitoring of Jets in Active Galactic Nuclei with VLBA Experiments. VIII. Faraday rotation in parsec-scale AGN jets
• What broad emission lines tell us about how active galactic nuclei work
• A unified accretion-ejection paradigm for Black Hole X-ray Binaries
• The intracluster magnetic field power spectrum in Abell 2255
• Magnetic fields in cluster cores: Faraday rotation in A400 and A2634
• The intracluster magnetic field power spectrum in Abell 2382
• The Origin and Evolution of Cosmic Magnetism
• Structures of the magnetoionic media around the FR I radio galaxies 3C 31 and Hydra A
• The Expanded Very Large Array
• Disk Formation in Magnetized Clouds Enabled by the Hall Effect
• Faraday rotation and polarization gradients in the jet of 3C~120: Interaction with the external medium and a helical magnetic field?
• Faraday Rotation Structure on Kiloparsec Scales in the Giant Radio Lobes of Centaurus A
• Parsec-scale Faraday Rotation Measures from General Relativistic MHD Simulations of Active Galactic Nuclei Jets
• Rotation Measures of Radio Sources in Hot Galaxy Clusters
• Magnetic Fields in the 3C 129 Cluster
• A Cosmic Battery
• A Study of 13 Powerful Classical Double Radio Galaxies
• The invariant Twist of Magnetic Fields in the Relativistic Jets of Active Galactic Nuclei
• Are Spine--Sheath Polarization Structures in the Jets of Active Galactic Nuclei Associated with Helical Magnetic Fields?
• Transverse Faraday-Rotation Gradients Across the Jets of 15 Active Galactic Nuclei
• Rotation-Measures across Parsec-scale Jets of FRI radio galaxies
• Are There Rotation Measure Gradients Across AGN Jets?
• A relativistic model of the radio jets in 3C 296
• Structure of the magnetoionic medium around the FR Class I radio galaxy 3C 449
• Theory of magnetically powered jets
• Connecting Magnetic Towers with Faraday Rotation Gradients in Active Galactic Nuclei Jets
• The Cosmic Battery Revisited
• Deep radio observations of 3C324 and 3C368: evidence for jet-cloud interactions
• Spectropolarimetry with the Allen Telescope Array: Faraday Rotation toward Bright Polarized Radio Galaxies
• The Cosmic Battery in Astrophysical Accretion Disks
• Measurement of the Electric Current in a Kpc-Scale Jet
• Studies of a sample of 6C radio galaxies at redshift one, I -- Deep multi-frequency radio observations
• Simulations of the Poynting--Robertson Cosmic Battery in Resistive Accretion Disks
• A Constraint on the Organization of the Galactic Center Magnetic Field Using Faraday Rotation
• Accretion disk radiation dynamics and the cosmic battery
• The depolarisation properties of powerful radio sources: breaking the radio-power vs. redshift degeneracy
• On the interpretation of the apparent existence of a preferred magnetic polarity in extragalactic jet sources
• The galactic magnetic field in the quasar 3C216
• Evidence for a Toroidal Magnetic-Field Component in 5C4.114 on Kiloparsec Scales
• Plasma physics in clusters of galaxies

Cited by in corpus (10)

• Parsec Scale Faraday-Rotation Structure Across the Jets of 9 Active Galactic Nuclei
• The Jets of AGN as giant co-axial cables
• Numerical simulations of the Cosmic Battery in accretion flows around astrophysical black holes
• The Spiderweb proto-cluster is being magnetized by its central radio jet
• 18-22 cm VLBA Faraday rotation studies of six AGN jets
• An underlying universal pattern in galaxy halo magnetic fields
• Depolarization and Faraday effects in AGN Jets
• The immediate environment of an astrophysical black hole
• The observed polarization direction depending on geometrical and kinematic parameters of relativistic jets
• On the Theoretical Framework of Magnetized Outflows from Stellar-Mass Black Holes and Related Observations