Linear polarization and flux density variations in the radio galaxy 3C120

Observations of the total flux density and linear polarization of 3C120 at 8 GHz from mid-1966 through mid-1974 are presented. The temporal variations in total flux density cannot be explained by the simple expanding-source model, and more complex models incorporating prolonged particle injection (or acceleration) and nonhomogeneous emitting regions are required. The polarization position angle remained near zero degrees during most of the observing period. Long-term trends in the polarization data suggest that the polarized emission was produced in the same physical region over a period of many outbursts. Comparison of the 8-GHz data with the polarization at other frequencies indicates that the polarized emission arises in a region which is partially opaque even between outbursts. Based upon the polarization position angle data the dominant direction of the magnetic field in the. emitting region until 1974 remained near the orientation of the extended source structure observed by VLB interferometry during 1971.