A Chandra - VLA Investigation of the X-ray Cavity System and Radio
  Mini-Halo in the Galaxy Cluster RBS 797
  We present a study of the cavity system in the galaxy cluster RBS 797 based
on Chandra and VLA data. RBS 797 (z = 0.35), is one of the most distant galaxy
clusters in which two pronounced X-ray cavities have been discovered. The
Chandra data confirm the presence of a cool core and indicate an higher
metallicity along the cavity directions. This is likely due to the AGN
outburst, which lifts cool metal-rich gas from the center along the cavities,
as seen in other systems. We find indications that the cavities are hotter than
the surrounding gas. Moreover, the new Chandra images show bright rims
contrasting with the deep, X-ray deficient cavities. The likely cause is that
the expanding 1.4 GHz radio lobes have displaced the gas, compressing it into a
shell that appears as bright cool arms. Finally we show that the large-scale
radio emission detected with our VLA observations may be classified as a radio
mini-halo, powered by the cooling flow (CF), as it nicely follows the trend
P_radio vs. P_CF predicted by the re-acceleration model.
