VLA observations of the radio continuum emission from Stephan's Quintet

Maps having angular resolutions of 2.25 and 6.0 arcsec have been prepared from 20-cm wavelength VLA observations of the radio continuum emission associated with Stephan's Quintet. The maps show that the ridge of radio emission between the galaxies NGC 7319 and NGC 7318b resolves into a point-like source which is perhaps an unrelated background object, and diffuse emission that partly coincides with spiral-arm regions in the latter galaxy. The central source in NGC 7319 is resolved in a direction perpendicular to the bar, and shows a jet-like feature. The interpretation given for these data, and for the lack of radio emission from NGC 7320, is the recent arrival of NGC 7318b to the group and its causing of the enhanced east side activity through interaction with an intergalactic medium.