The spectral shape and variability of the blazar 3C 446

Abstract

The radio to X-ray spectrum and variability of 3C 446 are discussed, and it is shown that the entire infrared-ultraviolet wavelength region exhibits strongly correlated variations, with the infrared and optical fluxes varying together on a time-scale of weeks or less. The variations in spectral shape which occur in the submillimeter to optical wavelength region are examined; it is proposed that continuous injection or reacceleration of the emitting electrons takes place during the observed flare events, and that the changes in spectral shape reflect the different effects that radiative energy losses have on the energy distribution of the electrons during and after such periods of injection or reacceleration. An overall brightening of the source observed throughout the millimeter to optical wavelength region between late 1968 and late 1983 is attributed to an increase in a slowly varying 'quiescent' emission component.