AN ULTRA-STEEP-SPECTRUM RADIO RELIC IN THE GALAXY CLUSTER A2443

Authors :: A.S. Cohen
Tracy E. Clarke
Source :: The Astronomical Journal. 141:149
Publication Year :: 2011
Publisher :: American Astronomical Society, 2011.
Abstract: 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.<br />AJ accepted, 15 pages, 10 figures (3 color), and two tables. Replacement corrects author order