Multifrequency observations of the superluminal quasar 3C 345
Abstract
The authors have investigated the continuum properties of the superluminal quasar 3C 345 with monitoring studies at radio, optical, infrared, and X-ray frequencies. The data presented here include optical, infrared, and radio measurements for a period of 20 yr, far-infrared fluxes obtained with IRAS, and X-ray fluxes taken with the Einstein Observatory. The second aspect of this work is the presentation and discussion of four simultaneous multifrequency spectra. These spectra, which extend from radio to ultraviolet frequencies, are analyzed to determine spectral shapes, total power, the connection between the spectral regions, and the details of spectral variation during outbursts. Simple theoretical considerations are applied to these data to estimate conditions in the emitting region. The ultraviolet and optical emission lines are compared to those of normal quasars and found to be an important discrimination for the issue of relativistic beaming.