The identification and nature of the powerful radio galaxy PKS 1934-63*

The compact radio source PKS 1934–63 is shown to lie within 0.26±0.2arcsec of the brighter component of the double optical image of the galaxy identification. Long-slit spectroscopy shows that the high-ionization emission-line region is spatially unresolved and is also coincident with the brighter galaxy component. The forbidden-line spectrum suggests that the densities in the NLR are somewhat higher than is usual in active nuclei, an observation which may be connected with the high power of the nuclear radio source. The K-line and G-band absorptions show a velocity difference of about 900 km s–1 between the stellar populations of the two galaxies. These new observations suggest that we are witnessing a close gravitational encounter, in contradiction with the dust-lane interpretation of the image doubling proposed by Penston & Fosbury. The firm identification of the radio source with an almost unresolved optical image provides another useful astrometric datum at a large Southern declination.