PKS 1934-638

PKS 1934-638, a galaxy with a Seyfert 2 nucleus (Fosbury et al. 1987), was most recently observed by Heckman et al. (1986) who obtained B and V images and by Fosbury et al. (1987) who present uncalibrated isophotes in R as well as spectra. The images show two galaxies in a common envelope with the brighter component coincident with the radio source. The spectra indicate a velocity difference of 900$\pm$300 km s^-1 between the two galaxies.

We have obtained on July 28, 1995 three 10 min images with EFOSC at the 3.6m telescope through a B and two through an I filter, under poor seeing conditions (2 - 25). The images may be fitted with two PSF's at the centers of the two galaxies and a r^1/4 law for the principal galaxy. A residue remains centered on the companion. Taking this to be part of the latter we obtain in a area of 186x126 (or 98x67 kpc) for the principal galaxy B=19.51$^{\rm m}$, I$_{\rm KC}$=16.87$^{\rm m}$ or B-I=2.64$^{\rm m}$ and for the companion B=20.84$^{\rm m}$, I$_{\rm KC}$=17.76$^{\rm m}$and B-I=3.08$^{\rm m}$. For a gE we would expect B-I=2.96$^{\rm m}$.Within the uncertainties the companion therefore appears to have about a normal colour for a gE, while the B-I colour of the principal galaxy appears to be 0.32$^{\rm m}$ too blue. The integrated B-I for the two galaxies is 2.72$^{\rm m}$ or $\sim0.2^{\rm m}$ too blue. In fact Heckman et al. (1986) found that the B-V colour of the two galaxies together is $\sim0.2^{\rm m}$ bluer than a normal elliptical would be, but did not notice a colour difference between them. Taking V₀-I₀=1.05$^{\rm m}$ for the principal galaxy and V₀-I₀=1.15$^{\rm m}$ for the companion we obtain for the two galaxies M$_{\rm V}=-$22.8$^{\rm m}$ and -21.7$^{\rm m}$ respectively.

The former value is rather typical for a strong radio galaxy, while the companion certainly should have a powerful influence on the radio galaxy if it is as close to it as it seems to be in projection (15 kpc). At the rather poor resolution of the available images the system looks only moderately perturbed, though the rather high density of stellar images in the field makes it difficult to decide which faint luminous patches belong to the galaxy.