HST Optical and Near UV Observations

Six images of the western hot spot were obtained on August 19, 1995 as part of GO program #5931 (PI Meisenheimer), three each in the F300W and F622W broadband filters. The images in each filter were dithered by several arc seconds in order to improve the effective spatial resolution of the images on the PC chip. However, the lack of duplicate exposures at each pointing, i.e., no CR-SPLIT, and the paucity of sources in the field greatly complicated attempts at alignment of the images. Instead, a number of cosmic rays were cleaned from each image by hand, and then the total number of sky-subtracted counts in the hot spot was determined for each frame. After averaging the results for each filter, the counts were converted to units of flux using the SYNPHOT package in IRAF. The derived values, as plotted in Fig. 6, are 30 $\mu$Jy and 104 $\mu$Jy for the F300W and F622W filters, respectively. The errors in these values have been estimated at 10%.