We present a detailed reanalysis of Chandra X-ray Observatory 
data for the galaxy cluster Abell 4059 and its central radio galaxy , PKS2354–35 .
We also present new 1.4 GHz and 4.7 GHz CnB-array radio data from the Very Large Array The VLA is part of the National Radio Astronomy Observatory which is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities , Inc . , as well as a short archival WFPC2 image from the Hubble Space Telescope .
The presence of a strong interaction between this radio galaxy and the intracluster medium ( ICM ) was suggested by Huang & Sarazin ( 1998 ) on the basis of a short observation by the High Resolution Imager on ROSAT , and confirmed in our preliminary analysis of the Chandra /ACIS-S data .
In particular , X-ray imaging clearly shows two cavities within the ICM that are approximately aligned with the radio-galaxy axis .
However , using our new radio maps ( which are at lower frequencies and better matched to searching for \sim 1 { \thinspace arcmin } structures than the previous high-quality maps ) we fail to find a detailed correspondence between the \sim 1 { \thinspace arcmin } 
scale radio-lobes and the ICM cavities .
This suggests that the cavities are “ ghosts ” of a previous burst of powerful activity by PKS 2354-35 .
This is supported by detailed , spatially-resolved , X-ray spectroscopy which fails to find any shock-heated ICM , suggesting that the cavities are evolving subsonically .
We also examine the nature of the central asymmetric ridge ( or bar ) of X-ray emission extending for \sim 30 { \thinspace kpc } south-west ( SW ) of the cluster center that has been noted in these previous analyzes .
We find the ridge to be denser and cooler than , but probably in pressure balance with , its surroundings .
The thermal evolution of this structure seems to be dominated by radiative cooling , possibly enhanced by the radio-galaxy ICM interaction .
We discuss several possible models for the formation of this SW ridge and find none of them to be entirely satisfactory .
In our preferred model , the SW ridge is due to radiative cooling induced by an interaction between a radio-galaxy driven disturbance and a pre-existing bulk ICM flow .
The presence of such a bulk flow ( with a velocity of \sim 500 { \thinspace km } { \thinspace s } ^ { -1 } 
projected on the plane of the sky ) is suggested by the off-center nature of the pair of X-ray cavities .
Such a bulk flow can be created during a cluster/sub-cluster merger — the presence of a prominent dust-lane in the cD galaxy of Abell 4059 , ESO 349-G010 , is circumstantial evidence for just such a merger .