Name of the Speaker(s): Chris Impey
Institution: Steward Observatory, University of Arizona
Title of the communication: Quasars and Blazars Across the Electromagnetic Spectrum
Preliminary abstract (12 lines max.):
A statistical analysis of 1 Jy radio sources shows that compact radio emission is correlated with evidence of strong synchrotron emission at far infrared and optical wavelengths. Soft X-rays originate in a different spectral component. The apparent fraction of highly polarized quasars diminishes with increasing redshift, due simply to dilution from the component believed to be a high temperature accretion disk, redshifted to optical wavelengths. BL Lac objects are systematically missing this hot component. These results are consistent with the same bulk relativistic Lorentz factor for emission at radio and optical wavelengths. Radio sources detected in gamma rays by EGRET are mostly blazars with strong radio emission and evidence for bulk relativistic motion. The mechanism for upscattering photons to gamma ray energies is still uncertain, since the EGRET detections are not notably compact in their radio emission. Flat spectrum radio sources contribute around 50% of the diffuse gamma ray background.