Chandra images of MS0735. Left: residual image after subtracting a double-β model from the X-ray image (0.5−7 keV). The image is in units of counts pixel⁻¹ and is Gaussian-smoothed with a 1 arcsec kernel radius. The dark regions to the north and south correspond to two large cavities, marked by blue ellipses. A surface brightness edge surrounds these cavities and corresponds to a weak shock front. The red ellipse marks the newly discovered intermediate cavity south-west of the core, while green ellipses show the inner cavities. Middle: same as before, with the LOFAR contours at 144 MHz superposed, and the smaller region outlined by the dashed red ellipse is considered to place a lower limit on the size of the intermediate cavity. Right: soft-band (0.3−1.0 keV) image in units of counts pixel⁻¹, Gaussian-smoothed with a 1 arcsec kernel radius. Two regions of low surface brightness, interpreted as a pair of cavities originating from a recent AGN outburst, are indicated with green ellipses. The LOFAR contours at 144 MHz and the blue and red ellipses showing the outer and intermediate cavities, respectively, are superposed.