Evidence for a merger-revived radio phoenix in MaxBCG
  J217.95869+13.53470
  We use XMM-Newton observations of the galaxy cluster MaxBCG
J217.95869+13.53470 to analyze its physical properties and dynamical state.
MaxBCG J217.95869+13.53470 is found at a redshift of 0.16, has a mass of
~1x10^14 Msun, and a luminosity of 7.9x10^43 erg/s. The temperature map shows
the presence of hot regions towards the north and west of the brightest cluster
galaxy (BCG). From the entropy distribution, regions of high entropy match the
location of the hot regions; more high entropy regions are found to the west,
and ~165 kpc to the southwest of the central AGN. A second X-ray bright galaxy
is visible ~90 kpc to the northeast of the BCG, at a redshift of 0.162. This
galaxy is likely to be the BCG of a smaller, infalling galaxy cluster. The mass
of the smaller cluster is ~10 percent the mass of MaxBCG J217.95869+13.53470,
yielding an impact parameter of ~30-100 kpc. We compare the results of our
X-ray observations with GMRT observations of the radio source VLSS
J1431.8+1331, located at the center of the cluster. Two sources are visible in
the radio: a central elongated source that bends at its northern and southern
ends, and a southwestern source that coincides with a region of high entropy.
The radio sources are connected by a bridge of faint radio emission. We
speculate that the southwestern radio source is a radio relic produced by
compression of old radio plasma by a merger shock.
