UV images of these three galaxies were obtained as part of an HST Cycle 5 program (GO 5944), using the FOC with the F/96 relay through the filter F210M ( 17#17 Å, 18#18 Å). This filter was selected because the bandpass does not include any strong emission lines and has a minimal red leak; therefore, the emission is dominated by the UV continuum at 2150 Å. The FOC was configured in the zoomed 512zoom11#111024 pixel format, with a field of view of about 1411#1114 arcsec. The integration time was 2000 s. A shorter exposure time (356 s) was also taken in the unzoomed 51211#11512 pixel configuration. The pixel size is 0.014 arcsec.
The data were processed with the HST pipeline software that includes the subtraction of a dark frame, correction for geometric distortion, flat-fielding, and flux calibration. We have also corrected for the non-linearity of the FOC using the algorithm of Baxter (1994) and a FOC linearity parameter a=0.73 for the 51211#11512 format and a=0.11 for the 512zoom11#111024 format. The maximum correction factor applied to the brightest pixels is 1.16, 1.07, and 1.05 for the 512zoom11#111024 format for NGC 7130, NGC 5135 and IC 3639, respectively. The corresponding factors for the 51211#11512 format are 1.02, 1.01 and 1.01.