HST
WFPC1 observations of 4C41.17 and 4C28.58 were obtained before the
refurbishment mission and the images required deconvolution to improve
the point spread
function (PSF). The individual images were bias subtracted and flat
fielded using the
normal calibration data. Then the individual exposures (generally 1
per orbit) were
combined and cosmic ray hits rejected. The images were then edited by
hand to remove
remaining artifacts and cosmic rays. A third order spline was fitted
to the background
and subtracted, The edited images were block replicated and deconvolved
using the Lucy
algorithm. The deconvolutions used model PSFs created with the "Tiny Tim"
module for
each filter assuming a B star model to match the color of the radio
galaxy. The PSFs were
modeled in the image plane at the position of the peak of the radio
galaxy emission. The
deconvolved and replicated images were then smoothed with a boxcar
algorithm. A grid of
deconvolutions and smoothed images were constructed with a range of
iterations in order
to select the best trade off between compact and diffuse emission.
The choice of the best results was made by eye.