Abstract. We present results based on the detailed analysis of deep XMM-Newton and Chandra observations of some clusters galaxies focusing on the investigation of cavities and discontinuities in the X-ray emission maps derived from their surface brightness study. Feedback from the AGN is believed to be the most promising mechanism for the formation and evolution of such cavities. We employed the contour binning, unsharp masking as well as 2D smooth model generation techniques for the investigation of such cavities and other hidden features in the selected targets. These cavities are of elliptical shapes, exist in pairs, and show a surface brightness decrement of several tens of percent. Spectroscopic analysis of X-ray emission extracted from different regions enabled us to examine the variations in derived parameters like X-ray luminosity, electron density, entropy, metal abundance, temperature, enthalpy, etc. Using the X-ray image deprojection technique we estimate the temperature and abundance gradient in the cavities of target clusters. Our results imply that these cavities are originated due to the AGN outflows associated with cluster cooling flow. We also derive various cavity properties like age, power, size and pressure which in turn enabled us to understand the mechanism of such cavity formation. Their association with radio jets implies that the heating and cooling in the clusters are coupled by feedback process.