NONALIGNED COMPONENTS IN EXTRAGALACTIC RADIO-SOURCES

Recent high resolution observations of ‘double’ radio sources show significant non-alignment of the structure within the components of the double in relation to the axis of the source. There is no clear relationship between the non-alignment in the two components of each source, nor any dependence of the magnitude of the non-alignment on other physical properties of the sources. The parent galaxies of these double sources are sometimes displaced from the straight line joining the outer radio peaks of the source. The non-alignment of the component structure could result from turbulent motions in the medium surrounding the radio source if the components are confined by ram-pressure and their velocities are 0.02c. In the ‘bubble’ model of Gull & Northover the observed structures would arise from asymmetries or irregularities in the distribution of the intracluster gas; this model also imposes limits on any motions in the gas. © 1974 Royal Astronomical Society.