The outer features. Left: unsharpmasked Chandra X-ray image of Abell 3581. An image, smoothed with a Gaussian with σ = 25 pixels has been subtracted from the original. The outer cavity is highlighted in green and the cold front in red. The two ‘bays’ to the east and south are indicated with dashed white ellipses. Middle: the X-ray surface brightness image after a smooth elliptical isophotal model was subtracted from the original data. The intensity scale was chosen to highlight the outer cavity and spiral. Right: the same regions overlaid on the X-ray temperature map.