Image of the central 150 kpc  ×  150 kpc region in the massive cluster of galaxies PKS 0745-191 (same field of view in all panels). North is up and east is left. Left: HST F850LP image, with the location of the central AGN in the BCG highlighted. The red box illustrates the region shown in Figure 3. Middle: Chandra 0.5–2.0 keV X-ray image of the cluster. The image has been smoothed with a Gaussian filter of σ = 2 pixels. The location of the central AGN and two X-ray cavities are shown. Right: unsharp-masked Chandra 0.5–2.0 keV image produced by smoothing the original image by a Gaussian filter of σ = 1 pixel and subtracting this by a smoothed image using a Gaussian filter of σ = 8 pixels. This image clearly reveals the X-ray cavities.