The Disk-Driven Jet of Cygnus A
Max-Planck-Institut für Radioastronomie, 53121 Bonn, Germany
Author to whom correspondence should be addressed.
Academic Editors: Jose L. Gomez, Alan P. Marscher and Svetlana G. Jorstad
Received: 5 September 2016 / Revised: 4 April 2017 / Accepted: 18 April 2017 / Published: 28 April 2017
Recently published results from VLBI observations at 3 and 7 millimeters of the radio galaxy Cygnus A are reviewed in this article, and discussed within the model of a prominently stratified jet outflow. At the source redshift (
0.056), mm-VLBI allows a spatial resolution down to 200 Schwarzschild radii to be achieved, providing an extremely detailed view of the two-sided jet base. Through a study of the kinematic properties of the flow and of its transverse structure, it is shown that the radio emission is produced by an accelerating, mildly relativistic, parabolically expanding disk-wind. The observed transverse stratification, both of the flux density and of the bulk speed, supports the presence of an invisible faster spine close to the jet axis, powered either by the inner regions of the accretion disk or by the spinning black hole.
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MDPI and ACS Style
Boccardi, B.; Krichbaum, T.P.; Bach, U. The Disk-Driven Jet of Cygnus A. Galaxies 2017, 5, 22.
Boccardi B, Krichbaum TP, Bach U. The Disk-Driven Jet of Cygnus A. Galaxies. 2017; 5(2):22.
Boccardi, Bia; Krichbaum, Thomas P.; Bach, Uwe. 2017. "The Disk-Driven Jet of Cygnus A." Galaxies 5, no. 2: 22.
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