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J. D. Linford et al. 2011 ApJ 726 16 doi:10.1088/0004-637X/726/1/16
J. D. Linford1, G. B. Taylor1, R. W. Romani2, S. E. Healey2, J. F. Helmboldt3, A. C. S. Readhead4, R. Reeves4, J. L. Richards4, and G. Cotter5
Show affiliationsThe radio properties of blazars detected by the Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope have been observed as part of the VLBA Imaging and Polarimetry Survey. This large, flux-limited sample of active galactic nuclei (AGNs) provides insights into the mechanism that produces strong γ-ray emission. At lower flux levels, radio flux density does not directly correlate with γ-ray flux. We find that the LAT-detected BL Lac objects tend to be similar to the non-LAT BL Lac objects, but that the LAT-detected FSRQs are often significantly different from the non-LAT FSRQs. The differences between the γ-ray loud and quiet FSRQs can be explained by Doppler boosting; these objects appear to require larger Doppler factors than those of the BL Lac objects. It is possible that the γ-ray loud FSRQs are fundamentally different from the γ-ray quiet FSRQs. Strong polarization at the base of the jet appears to be a signature for γ-ray loud AGNs.
galaxies: active; galaxies: jets; galaxies: nuclei; gamma rays: galaxies; radio continuum: galaxies
Issue 1 (2011 January 1)
Received 2010 August 4, accepted for publication 2010 October 27
Published 2010 December 9
Total article downloads: 475
J. D. Linford et al. 2011 ApJ 726 16
