The structure of the nucleus of the Seyfert galaxy NGC 1275

The nucleus of the Seyfert galaxy NGC 1275 has been surveyed at 1.35-cm wavelength with the Haystack-Green Bank-Effelsberg-Onsala-Crimea radio-interferometer network. Its structure comprises eastern and western systems of features, separated by 0.7 pc. The eastern system has a core embedded in an absorbing medium whose electron density depends on distance L as 4 x 10 to the 45th L exp -2.3 + or - 0.5. The compact components, which measure about 0.0001 arcsec across, have a magnetic field strength of about 0.3 gauss. All fine-structure components maintain stable positions, but their brightness is variable. The radio brightness distribution is probably governed by the magnetic field structure.