Tracing Ghost Cavities with Low Frequency Radio Observations
  We present X-ray and multi-frequency radio observations of the central radio sources in several X-ray cavity systems. We show that targeted radio observations are key to determining if the lobes are being actively fed by the central AGN. Low frequency observations provide a unique way to study both the lifecycle of the central radio source as well as its energy input into the ICM over several outburst episodes. 
Tracy Clarke (1,2), Elizabeth Blanton (3), Craig Sarazin (4), Namir   Kassim (1), Loren Anderson (3), Henrique Schmitt (1,2)...