Optical Morphology

Figure 3: HST-WFPC-2 image of the A4059 field (see §2.3 for details of the observation). The cD galaxy ESO349-G010 is clearly visible on the PC-chip.

Figure 4: WFPC-2 imaging of the cD galaxy ESO349-G010, the host galaxy of the radio source PKS2354-35 (see §2.3 for details of the observation). Note the prominent dust lane crossing the galaxy from the north-east to the south-west.

Figure 3 shows the HST/WFPC-2 image of the A4059 field. While an analysis of the optical galaxy cluster is beyond the scope of this paper, a large number of bright galaxies can be seen. By far the brightest, however, is the cD galaxy ESO349-G010 which has been placed on the PC-chip. The detailed high resolution PC image of ESO349-G010 is shown in Fig. 4. The most striking feature is the prominent dust lane that can be traced for at least 5arcsec (corresponding to 5kpc) projected across the central regions of the galaxy. The position angle of the dust lane is twisted by $60-70^\circ$ relative to the radio axis of PKS2354-35, and coincides with the position angle of the bright SW ridge in the X-ray image. Similar dust lanes, also oriented roughly perpendicular to the radio axis, have been noted in HST data for the host galaxies of three Compact Symmetric Objects (CSOs) by Perlman et al. (2001). The Perlman et al. CSO-hosts also possess disturbed outer isophotes that suggest a significant merger event approximately $\sim 10^8{\rm\thinspace yr}$ ago. Since it was taken as part of a snap-shot campaign, the data for ESO349-G010 lack the multi-band coverage and signal-to-noise to perform the Perlman et al. analysis.