A Caltech Library Service

Doppler boosting, superluminal motion, and the kinematics of AGN jets

Kellermann, K. I. and Kovalev, Y. Y. and Lister, M. L. and Homan, D. C. and Kadler, M. and Cohen, M. H. and Ros, E. and Zensus, J. A. and Vermeulen, R. C. and Aller, M. F. and Aller, H. D. (2007) Doppler boosting, superluminal motion, and the kinematics of AGN jets. Astrophysics and Space Science, 311 (1-3). pp. 231-239. ISSN 0004-640X. doi:10.1007/s10509-007-9622-5.

Full text is not posted in this repository. Consult Related URLs below.

Use this Persistent URL to link to this item:


We discuss results from a decade long program to study the fine-scale structure and the kinematics of relativistic AGN jets with the aim of better understanding the acceleration and collimation of the relativistic plasma forming AGN jets. From the observed distribution of brightness temperature, apparent velocity, flux density, time variability, and apparent luminosity, the intrinsic properties of the jets including Lorentz factor, luminosity, orientation, and brightness temperature are discussed. Special attention is given to the jet in M87, which has been studied over a wide range of wavelengths and which, due to its proximity, is observed with excellent spatial resolution. Most radio jets appear quite linear, but we also observe curved non-linear jets and non-radial motions. Sometimes, different features in a given jet appear to follow the same curved path but there is evidence for ballistic trajectories as well. The data are best fit with a distribution of Lorentz factors extending up to γ∼30 and intrinsic luminosity up to ~10^(26) W  Hz^(−1). In general, gamma-ray quasars may have somewhat larger Lorentz factors than non gamma-ray quasars. Initially the observed brightness temperature near the base of the jet extend up to ~5×10^(13) K which is well in excess of the inverse Compton limit and corresponds to a large excess of particle energy over magnetic energy. However, more typically, the observed brightness temperatures are ~2×10^(11) K, i.e., closer to equipartition.

Item Type:Article
Related URLs:
URLURL TypeDescription ReadCube access
Kellermann, K. I.0000-0002-0093-4917
Kovalev, Y. Y.0000-0001-9303-3263
Lister, M. L.0000-0003-1315-3412
Homan, D. C.0000-0002-4431-0890
Ros, E.0000-0001-9503-4892
Aller, M. F.0000-0003-2483-2103
Additional Information:© 2007 Springer Science+Business Media B.V. Received: 10 April 2007; Accepted: 31 July 2007; Published online: 1 September 2007. This paper is based on observations made with the Very Long Baseline Array which is a facility of the National Radio Astronomy Observatory which is operated by Associated Universities, Inc., under a cooperative agreement with the National Science Foundation. Part of this work was done by YYK, MLL and DCH during their Karl Jansky postdoctoral fellowship at the National Radio Astronomy Observatory. YYK is currently a Research Fellow of the Alexander von Humboldt Foundation. DCH was partially supported by an award from the Research Corporation. MK was supported in part through a stipend from the International Max Planck Research School for Radio Astronomy at the University of Bonn and, in part, by a NASA Postdoctoral Program Fellowship appointment at the Goddard Space Flight Center. The MOJAVE project is supported under National Science Foundation grant AST-0406923 and a grant from the Purdue Research Foundation. The work at the RATAN-600 radio telescope was supported by the Russian Ministry of Education and Science, the NASA JURRISS Program (project W-19611), and the Russian Foundation for Basic Research (grants 01-02-16812 and 05-02-17377). The University of Michigan Radio Astronomy Observatory is supported by the University of Michigan and the National Science Foundation (grant AST- 0607523).
Funding AgencyGrant Number
Research CorporationUNSPECIFIED
International Max Planck Research School for Radio AstronomyUNSPECIFIED
NASA Postdoctoral Program FellowshipUNSPECIFIED
Subject Keywords:Galaxies: active; Galaxies: jets; Galaxies: individual (M87); Quasars: general; Radio continuum: galaxies; Acceleration of particles
Issue or Number:1-3
Record Number:CaltechAUTHORS:20100923-111741692
Persistent URL:
Official Citation:Kellermann, K.I., Kovalev, Y.Y., Lister, M.L. et al. Doppler boosting, superluminal motion, and the kinematics of AGN jets. Astrophys Space Sci 311, 231–239 (2007).
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:20098
Deposited By: Jason Perez
Deposited On:24 Sep 2010 17:47
Last Modified:08 Nov 2021 23:57

Repository Staff Only: item control page