A synchrotron radiation model for extragalactic infrared sources

For a number of extragalactic sources of infrared radiation, for example some quasars and nuclei of Class I Seyfert galaxies that are also radio sources, there is a characteristic maximum in the radiation spectrum atv10¹¹ Hz. We discuss a model in which this feature is regarded as intrinsic to the process of electron production, and in which the radiation is produced by the synchrotron mechanism. A two-component version of the model can be employed in the interpretation of the composite radiation spectra of several sources — 3C 84 (NGC 1275), 3C 120 and 3C 273.