Optical images of the three galaxies were retrieved from the HST archive. The images were obtained with the HST WFPC2 through the filter F606W ( 20#20=6010.6 Å, 21#21=1497 Å). The bandpass of this filter includes strong emission lines as [OIII] and H9#9. The integration times were 500 s for each image. The pixel size of the PC, where the central region of these galaxies falls, is 0.046 arcsec/pixel. Figure 1 shows a global view of each galaxy.
NGC 7130 looks very asymmetric, with a spiral arm to the North-West being more distorted and less organized than the arm to the South-East. This is probably related to the presence of the dwarf companion galaxy located to the North-West of NGC 7130. The bar seen in the NIR at P.A=08#8 (Mulchaey et al 1997) is not seen in the WFPC2 image; however, we detect two spiral arm segments located in the outer part of two dust lanes that run in the North-South direction toward the center (Figure 1a). These lanes could be tracing the leading edge of the NIR bar. The inner structure is boxy with the major axis aligned at P.A.=908#8, perpendicular to the NIR bar.
The WFPC2 image of NGC 5135 shows the bar and the two spiral arms emerging from it. Two inner spiral arm segments located at the outer part of two dust lines are clearly detected in the WFPC2 image (Figure 1b). These segments seem to be spiraling to the center, and they could be located along the leading edge of the bar.
IC 3639 clearly shows its bar at P.A.=1508#8 and two spiral arms emerging from the edges of the bar. This galaxy does not show obvious signs of interaction.
In the three galaxies, the central 1 arcsec is resolved into several structures that will be described in the next section when we compare them with the UV images.