Diffuse Radio Emission in/around the Coma Cluster: Beyond Simple
  Accretion
  We report on new 1.41 GHz Green Bank Telescope and 352 MHz Westerbork
Synthesis Radio Telescope observations of the Coma cluster and its environs. At
1.41 GHz we tentatively detect an extension to the Coma cluster radio relic
source 1253+275 which makes its total extent ~2 Mpc. This extended relic is
linearly polarized as seen in our GBT data, the NVSS, and archival images,
strengthening a shock interpretation. The extended relic borders a previously
undetected "wall" of galaxies in the infall region of the Coma cluster. We
suggest that the radio relic is an infall shock, as opposed to the outgoing
merger shocks believed responsible for other radio relics. We also find a sharp
edge, or "front", on the western side of the 352 MHz radio halo. This front is
coincident with a similar discontinuity in the X-ray surface brightness and
temperature in its southern half, suggesting a primary shock-acceleration
origin for the local synchrotron emitting electrons. The northern half of the
synchrotron front is less well correlated with the X-ray properties, perhaps
due to projection effects. We confirm the global pixel-to-pixel power-law
correlation between the 352 MHz radio brightness and X-ray brightness with a
slope that is inconsistent with predictions of either primary shock
acceleration or secondary production of relativistic electrons in Giant Radio
Halos, but is allowable in the framework of the turbulent re-acceleration of
relic plasma. The failure of these first order models and the need for a more
comprehensive view of the intracluster medium energization is also highlighted
by the very different shapes of the diffuse radio and X-ray emission. We note
the puzzling correspondence between the shape of the brighter regions of the
radio halo and the surface mass density derived from weak lensing.
