An Ultra-Steep Spectrum Radio Relic in the Galaxy Cluster Abell 2443
  We present newly discovered radio emission in the galaxy cluster Abell 2443
which is (1) diffuse, (2) extremely steep spectrum, (3) offset from the cluster
center, (4) of irregular morphology and (5) not clearly associated with any of
the galaxies within the cluster. The most likely explanation is that this
emission is a cluster radio relic, associated with a cluster merger. We present
deep observations of Abell 2443 at multiple low frequencies (1425, 325 and 74
MHz) which help characterize the spectrum and morphology of this relic. Based
on the curved spectral shape of the relic emission and the presence of small
scale structure, we suggest that this new source is likely a member of the
radio phoenix class of radio relics.
