Structure of the compact radio sources in NGC 1052 and NGC 4278

The nuclear radio continuum sources in the elliptical galaxies NGC 1052 and NGC 4278 have been observed with VLBI at 6 cm (both galaxies) and 18 cm (NGC 4278). The resulting maps show the milliarcsec-scale structure of NGC 1052 to be extended along a position angle which is close to the projected rotation axis of the neutral hydrogen (H I) gas. A similar situation is found for the elliptical galaxy NGC 4278, and suggests that the nuclear 'engines' in these galaxies have been fueled by infalling H I. In both cases, there is evidence that the H I infall may have been caused by a gravitational interaction with a nearby spiral galaxy.