Wideband VLA Observations of Abell 2256 I: Continuum, Rotation Measure
  and Spectral Imaging
  We report new observations of Abell 2256 with the Karl G. Jansky Very Large
Array (VLA) at frequencies between 1 and 8 GHz. These observations take
advantage of the 2:1 bandwidths available for a single observation to study the
spectral index, polarization and Rotation Measure as well as using the
associated higher sensitivity to image total intensity features down to ~0.5"
resolution. We find the Large Relic, which dominates the cluster, is made up of
a complex of filaments which show correlated distributions in intensity,
spectral index, and fractional polarization. The Rotation Measure varies across
the face of the Large Relic but is not well correlated with the other
properties of the source. The shape of individual filaments suggests that the
Large Relic is at least 25 kpc thick. We detect a low surface brightness arc
connecting the Large Relic to the Halo and other radio structures suggesting a
physical connection between these features. The center of the F-complex is
dominated by a very steep-spectrum, polarized, ring-like structure, F2, without
an obvious optical identification, but the entire F-complex has interesting
morphological similarities to the radio structure of NGC1265. Source C, the
Long Tail, is unresolved in width near the galaxy core and is </~100pc in
diameter there. This morphology suggests either that C is a one-sided jet or
that the bending of the tails takes place very near the core, consistent with
the parent galaxy having undergone extreme stripping. Overall it seems that
many of the unusual phenomena can be understood in the context of Abell 2256
being near the pericenter of a slightly off-axis merger between a cluster and a
smaller group. Given the lack of evidence for a strong shock associated with
the Large Relic, other models should be considered, such as reconnection
between two large-scale magnetic domains.
