Multi-epoch VLBA observations of gamma-ray bright blazars

Marscher, Alan P.; Marchenko, Svetlana G.; Mattox, John R.; Hallum, Jeremy; Wehrle, Ann E.; Bloom, Steven D.
April 2000
AIP Conference Proceedings;2000, Vol. 510 Issue 1, p362
Academic Journal
We report some of the statistical results from our multi-epoch VLBA study of motions in the jets of 42 γ-ray bright blazars. The apparent velocities are high, which agrees with the expectations of inverse Compton models in which the γ rays are more highly beamed than is the radio synchrotron radiation. We find evidence that the apparent speeds are higher farther from the core, which can be explained best by bending from a viewing angle near zero to one closer to sin[sup -1](Γ[sup -1]), rather than by increasing Lorentz factors. In 25 of the sources in the sample, there is at least one non-core component that appears to be stationary during our observations. We offer explanations for these results. © 2000 American Institute of Physics.


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