Fig. 9. ROSAT (0.1-2.4 keV) PSPC map of the IC 4329A field obtained using an adaptive filtering technique (see text), overlayed on a digitized sky survey image. The contour levels are at 2, 3, 5, 9, 15, 31, 63, 127, 255, 511, 1023 and 2047 ( being cts s^-1 arcmin^-2) above the background ( cts s^-1 arcmin^-2).